1. Technical Field
The embodiments herein are generally related to a construction and civil engineering industry. The embodiments herein are particularly related to I-form beams used in construction and civil engineering industry. The embodiments herein are more particularly related to a hot-rolled semi light weight, medium I-flange beam with higher strength, higher resistance, and less load on structural elements in the construction.
2. Description of the Related Art
The use of engineered beams in constructions has become common place particularly for use as a component in floors and joists. Beams are structural elements that are capable of withstanding load primarily by resisting bending. Beams are characterized by their profile (shape of cross-section), length, and type of material used. Steel beams are lighter in weight and less prone to warping when compared with solid wood joists.
Most beams used in steel constructions have an I or H shaped beams that are capable of supporting higher loads than an equivalent sized dimensional lumber beam and are therefore an economic means of construction. I-beams are also known as H-beams, W-beams (for wide flange), Universal Beams (UB), Rolled Steel Joists (RSJ), or a double-T beams. I-beams are usually made of structural steel and are used in construction and civil engineering. The horizontal elements of the I-beam are known as flanges, while the vertical element is termed as the web. The height of the cross section in the I-beam is higher than the width of the flanges.
There are two standard types of I-beam forms: a rolled I-beam, and a plate girder. The rolled I-beam is formed by hot rolling and cold rolling or extrusion (depending on material). The plate girder type of beam is formed by using welding (or occasionally bolting or riveting) plates.
The existing flange beam standards present various challenges in today's construction field. These standards cover flange beams with more weight which consume more raw materials and energy during the production or manufacturing process. Due to heavy weight, a cost of transportation of the flange beams to a construction site increases. Also, the construction workers face challenges while assembling the flange beams in the construction. Moreover, the flange beams manufactured with the existing standards impose more load on the structural elements after the construction.
Hence there is a need for a hot-rolled semi light weight, medium flange (I-7) beams with more strength and resistance when compared with the existing I-flange beams. There is also a need for a hot-rolled semi light weight, medium flange (I-7) beam that imposes less load on structural elements in the construction. There is also a need for a hot-rolled semi light weight, medium flange (I-7) beam that eases the use of the flange beams at the construction site and reduces the cost to transport flange beams to the construction site.
The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
The primary object of the embodiments herein is to provide a hot-rolled semi light weight, medium I-flange (I-7) beam with more strength and resistance when compared with the existing l-flange beam standards.
Another object of the embodiments herein is to provide a hot-rolled semi light weight, medium flange (I-7) beam that imposes less load on structural elements in the construction.
Yet another object of the embodiments herein is to provide a hot-rolled semi light weight, medium flange (I-7) beam that eases the use of the flange beams at a construction site and reduces the cost to transport the flange beams to the construction site.
Yet another object of the embodiments herein is to provide a hot-rolled semi light weight, medium flange (I-7) beam that is cheaper than the existing flange beams and uses less raw materials and energy during the manufacturing process.
Yet another object of the embodiments herein is to manufacture a hot-rolled semi light weight, medium flange (I-7) beam that is free from defects such as crack, delamination, tear, non-metallic inclusion, and fold.
These and other objects and advantages of the embodiments herein will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
The following details present a simplified summary of the embodiments herein to provide a basic understanding of some aspects of the embodiments herein. This summary is not an extensive overview of the embodiments herein. It is not intended to identify key/critical elements of the embodiments herein or to delineate the scope of the embodiments herein. Its sole purpose is to present some concept of the embodiments herein in a simplified form as a prelude to the more detailed description that is presented later.
The other objects and advantages of the embodiments herein will become readily apparent from the following description taken in conjunction with the accompanying drawings.
According to an embodiment herein, a hot-rolled semi light weight, medium flange (I-7) beam is provided. The beam comprises an upper flange; a lower flange; and a web.
According to an embodiment herein, the web extends between the lower flange and the upper flange. The upper flange is perpendicular to the web and the lower flange is perpendicular to the web. The web separates the upper flange and the lower flange with a height (h). The web has a thickness (s). The upper flange and the lower flange has an equal width (b). The upper flange and the lower flange has an equal thickness (t). The flange beam is made up of a steel alloy and wherein the steel alloy is selected from a group consisting of steel 275 type alloy and steel 295 type alloy.
According to an embodiment herein, the beam is identified using an identifier. The identifier of the beam comprises an abbreviation, a beam number, and a minimum yield strength of the steel alloy in N/mm2.
According to an embodiment herein, the steel 275 type alloy comprises a carbon (C) at a quantity of 0.18%, a manganese (Mn) at a quantity of 1.50%, a phosphorus (P) at a quantity of 0.030%, a sulfur (S) at a quantity of 0.030%, a nitrogen (N) at a quantity of 0.012%, a cupper (Cu) at a quantity of 0.55%, and a Carbonequivalent (Ceq) at a quantity of 0.40%. The Carbonequivalent (Ceq) is equal to sum of (Carbon (C)+Manganese (Mn))/6+(Chromium (Cr)+Vanadium (V)+Molyb-denum (Mo))/5+Cupper (Cu)+Nickel (Ni))/15.
According to an embodiment herein, the steel 295 type alloy comprises a carbon (C) at a quantity of 0.20%, a silicon (Si) at a quantity of 0.50%, a manganese (Mn) at a quantity of 1.50%, a phosphorus (P) at a quantity of 0.025%, a sulfur (S) at a quantity of 0.025%, a nitrogen (N) at a quantity of 0.012%, a cupper (Cu) at a quantity of 0.45%, and a Carbonequivalent (Ceq) at a quantity of 0.40%. The Carbonequivalent (Ceq) is equal to sum of (Carbon (C)+Manganese (Mn))/6+Chromium (Cr)+Vanadium (V)+Molyb-denum (Mo))/5+Cupper (Cu)+Nickel (Ni))/15.
According to an embodiment herein, a tilt of the upper flange is measured in relation to the web. The tilt of the upper flange has a maximum allowable flange tilt. A tilt of the lower flange is measured in relation to the web. The tilt of the lower flange has the maximum allowable flange tilt and the maximum allowable flange tilt is 1.5 mm when the width (b) of the flange is less than or equal to 110 mm.
According to an embodiment herein, the upper flange is symmetrical with respect to the web and the lower flange is symmetrical with respect to the web.
According to an embodiment herein, the thickness (s) of the lower flange is measured at a distance of one fourth of a total width (b) of the lower flange.
According to an embodiment herein, the height (h) of the web is equal to an outer distance between the upper flange and the lower flange along a cross axis of the web.
According to an embodiment herein, the chemical components of the steel 275 type alloy and the steel 295 type alloy have tolerance in relation to percentage weight. A tolerance of the carbon (C) in relation to percentage weight is +0.03. A tolerance of the silicon (Si) in relation to percentage weight is within range of +0.05 to +0.010. A tolerance of the Manganese (Mn) in relation to percentage weight is +0.10. A tolerance of the phosphorus (P) in relation to percentage weight is +0.010. A tolerance of the nitrogen (N) in relation to percentage weight is +0.0020. A tolerance of the Cupper (Cu) in relation to percentage weight is +0.05.
According to an embodiment herein, the beam has a weight (G) with an allowable weight tolerance. The maximum allowable weight tolerance is equal to ±4% of a nominal weight of the flange (I-7) beam.
According to an embodiment herein, the beam has an effective length (L) with an allowable length tolerance. The allowable length tolerance of a normal product with a fixed length up to 12000 mm is ±50 mm. The allowable length tolerance of a custom built product with a given length up to 15000 mm is ±5 mm or ±10 mm or ±25 mm.
According to an embodiment herein, a transverse shear stress produces a tilt in the beam. The beam has a maximum allowable tilt of transverse shear. The maximum allowable tilt of transverse shear is measured in relation to the height (h). The maximum allowable tilt of transverse shear in relation to the height (h) is 1.6% of the height (h).
According to an embodiment herein, the maximum allowable tilt of transverse shear is measured in relation to the width (b). The maximum allowable tilt of transverse shear in relation to the width (b) is 1.0% of the width (b).
According to an embodiment herein, the beam has a maximum asymmetry and the maximum asymmetry of the flange beam is 2.5 mm.
According to an embodiment herein, the beam has a straightness. The straightness of the beam is measured using a straight edge as a reference. The beam has a maximum tolerance of deviation from straightness. The maximum tolerance of deviation from straightness is 0.0030 mm when the height (h) is within a range of 120 mm to 80 mm. The maximum tolerance of deviation from straightness is 0.0015 mm when the height (h) is 200 mm.
According to an embodiment herein, the beam has a maximum web curvature (f). The maximum curvature (f) is 1.0 mm when the beam number is 12. The maximum curvature (f) is 1.5 mm when the beam number is a range of 14 to 20.
According to an embodiment herein, a method is provided for producing a hot-rolled semi light weight, medium flange (I-7) beam. The method comprising steps of cutting a steel ingot into pieces of a preset length and the steel ingot is made up of a steel alloy. The steel ingot pieces are placed inside a heating furnace for melting the steel alloy. The melted steel ingot pieces are passing through a rolling assembly. The rolling assembly reduces a thickness of the steel ingot pieces to a uniform level along an entire length of the steel ingot pieces. The rolled steel ingot pieces are cut into custom sizes using a plurality of saws. The steel ingot pieces are passed through a cooling bed and a straightener there by forming a semi light weight, medium flange (I-7) beam.
According to an embodiment herein, the preset length of the steel ingot pieces is within a range of 3.2 to 4.2 meters.
According to an embodiment herein, the rolling assembly comprises a plurality of primary rolling stands, a plurality of middle rolling stands, and a plurality of final rolling stands.
According to an embodiment herein, the furnace is maintained at a preset temperature, and wherein the preset temperature is of 1350° C.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
Although the specific features of the embodiments herein are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the embodiment herein.
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. The embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
According to an embodiment herein, a hot-rolled semi light weight, medium flange (I-7) beam is provided. The beam comprises an upper flange; a lower flange; and a web.
According to an embodiment herein, the web extends between the lower flange and the upper flange. The upper flange is perpendicular to the web and the lower flange is perpendicular to the web. The web separates the upper flange and the lower flange with a height (h). The web has a thickness (s). The upper flange and the lower flange has an equal width (b). The upper flange and the lower flange has an equal thickness (t). The flange beam is made up of a steel alloy and wherein the steel alloy is selected from a group consisting of steel 275 type alloy and steel 295 type alloy.
According to an embodiment herein, the beam is identified using an identifier. The identifier of the beam comprises an abbreviation, a beam number, and a minimum yield strength of the steel alloy in N/mm2.
According to an embodiment herein, the steel 275 type alloy comprises a carbon (C) at a quantity of 0.18%, a manganese (Mn) at a quantity of 1.50%, a phosphorus (P) at a quantity of 0.030%, a sulfur (S) at a quantity of 0.030%, a nitrogen (N) at a quantity of 0.012%, a cupper (Cu) at a quantity of 0.55%, and a Carbon equivalent (Ceq) at a quantity of 0.40%. The Carbon equivalent (Ceq) is equal to sum of (Carbon (C)+Manganese (Mn))/6+(Chromium (Cr)+Vanadium (V)+Molyb-denum (Mo))/5+Cupper (Cu)+Nickel (Ni))/15.
According to an embodiment herein, the steel 295 type alloy comprises a carbon (C) at a quantity of 0.20%, a silicon (Si) at a quantity of 0.50%, a manganese (Mn) at a quantity of 1.50%, a phosphorus (P) at a quantity of 0.025%, a sulfur (S) at a quantity of 0.025%, a nitrogen (N) at a quantity of 0.012%, a cupper (Cu) at a quantity of 0.45%, and a Carbonequivalent (Ceq) at a quantity of 0.40%. The Carbonequivalent (Ceq) is equal to sum of (Carbon (C)+Manganese (Mn))/6+Chromium (Cr)+Vanadium (V)+Molyb-denum (Mo))/5+Cupper (Cu)+Nickel (Ni))/15.
According to an embodiment herein, a tilt of the upper flange is measured in relation to the web. The tilt of the upper flange has a maximum allowable flange tilt. A tilt of the lower flange is measured in relation to the web. The tilt of the lower flange has the maximum allowable flange tilt and the maximum allowable flange tilt is 1.5 mm when the width (b) of the flange is less than or equal to 110 mm.
According to an embodiment herein, the upper flange is symmetrical with respect to the web and the lower flange is symmetrical with respect to the web.
According to an embodiment herein, the thickness (s) of the lower flange is measured at a distance of one fourth of a total width (b) of the lower flange.
According to an embodiment herein, the height (h) of the web is equal to an outer distance between the upper flange and the lower flange along a cross axis of the web.
According to an embodiment herein, the chemical components of the steel 275 type alloy and the steel 295 type alloy have tolerance in relation to percentage weight. A tolerance of the carbon (C) in relation to percentage weight is +0.03. A tolerance of the silicon (Si) in relation to percentage weight is within range of +0.05 to +0.010. A tolerance of the Manganese (Mn) in relation to percentage weight is +0.10. A tolerance of the phosphorus (P) in relation to percentage weight is +0.010. A tolerance of the nitrogen (N) in relation to percentage weight is +0.0020. A tolerance of the Cupper (Cu) in relation to percentage weight is +0.05.
According to an embodiment herein, the beam has a weight (0) with an allowable weight tolerance. The maximum allowable weight tolerance is equal to ±4% of a nominal weight of the flange (I-7) beam.
According to an embodiment herein, the beam has an effective length (L) with an allowable length tolerance. The allowable length tolerance of a normal product with a fixed length up to 12000 mm is ±50 mm. The allowable length tolerance of a custom built product with a given length up to 15000 mm is ±5 mm or ±10 mm or ±25 mm.
According to an embodiment herein, a transverse shear stress produces a tilt in the beam. The beam has a maximum allowable tilt of transverse shear. The maximum allowable tilt of transverse shear is measured in relation to the height (h). The maximum allowable tilt of transverse shear in relation to the height (h) is 1.6% of the height (h).
According to an embodiment herein, the maximum allowable tilt of transverse shear is measured in relation to the width (b). The maximum allowable tilt of transverse shear in relation to the width (b) is 1.0% of the width (b).
According to an embodiment herein, the beam has a maximum asymmetry and the maximum asymmetry of the flange beam is 2.5 mm.
According to an embodiment herein, the beam has a straightness. The straightness of the beam is measured using a straight edge as a reference. The beam has a maximum tolerance of deviation from straightness. The maximum tolerance of deviation from straightness is 0.0030 mm when the height (h) is within a range of 120 mm to 80 mm. The maximum tolerance of deviation from straightness is 0.0015 mm when the height (h) is 200) mm.
According to an embodiment herein, the beam has a maximum web curvature (f). The maximum curvature (f) is 1.0 mm when the beam number is 12. The maximum curvature (f) is 1.5 mm when the beam number is a range of 14 to 20.
According to an embodiment herein, a method is provided for producing a hot-rolled semi light weight, medium flange (I-7) beam. The method comprising steps of cutting a steel ingot into pieces of a preset length and the steel ingot is made up of a steel alloy. The steel ingot pieces are placed inside a heating furnace for melting the steel alloy. The melted steel ingot pieces are passing through a rolling assembly. The rolling assembly reduces a thickness of the steel ingot pieces to a uniform level along an entire length of the steel ingot pieces. The rolled steel ingot pieces are cut into custom sizes using a plurality of saws. The steel ingot pieces are passed through a cooling bed and a straightener there by forming a semi light weight, medium flange (I-7) beam.
According to an embodiment herein, the preset length of the steel ingot pieces is within a range of 3.2 to 4.2 meters.
According to an embodiment herein, the rolling assembly comprises a plurality of primary rolling stands, a plurality of middle rolling stands, and a plurality of final rolling stands.
According to an embodiment herein, the furnace is maintained at a preset temperature, and wherein the preset temperature is of 1350° C.
According to an embodiment herein, a hot-rolled semi light weight, medium flange (I-7) beam is provided. The hot-rolled semi light weight, medium flange (I-7) beam comprises a vertical element known as web and two horizontal parallel edges known as flanges. The web connects the two parallel edges and forms the flange (I-7) beam. The web resists shear forces experienced by the flange (I-7) beam, while the flanges resist bending moment experienced by the flange (I-7) beam. The thickness of the flange (I-7) beam is measured at one fourth distance of the flange width (b). The beam height (h) of the flange (I-7) beam is equal to an outer distance between the two flanges across the axis of the web. Beam number of the flange (I-7) beam indicates nominal height of the beam in centimeters. A bundle of flange (I-7) beams comprises a set of beams tied using at least two wires or straps.
According to an embodiment herein, an identifier of the flange (I-7) beam comprises an abbreviation, beam number and minimum yield strength of steel in N/mm2. For example, A (I-7) beam with beam number 16 and minimum steel yield strength of 275 N/mm2 is indicated as I-7-16-275.
According to an embodiment herein, nominal dimensions, sizes and static parameters of the flange (I-7) beam are provided in Table 1.
According to an embodiment herein, the height (h) of the flange (I-7) beam is measured on central line of the web thickness (s). The thickness (s) of the web is measured at central point of the web after the beam height (h). The thickness (t) of the flange is measured at one fourth distance from edge of the flange. The tolerance values of the beam height (h), flange width (b), web thickness (s), and flange thickness (t) of the flange (I-7) beam are provided in Table 2.
According to an embodiment herein, the maximum weight tolerance of the flange (I-7) beam is equal to ±4% of the normal weight of the flange (I-7) beam. The weight deviation is equal to a difference between bundle/piece true weight and computational weight of the flange (I-7) beam.
According to an embodiment herein, the weight values shown in Table 1 are calculated based on density of steel which is equal to 7850/m3.
According to an embodiment herein, the flange (I-7) beam is made up of a steel alloy comprising carbon (C), manganese (Mn), silica (Si), phosphorus (P), sulfur (S), a nitrogen (N), a cupper (Cu), and a Carbonequivalent (Ceq).
Carbonequivalent(Ceq)=(C+Mn)/6(Cr+V+Mo)/5+(Cu+Ni)/15 (1)
Where C: Carbon, Mn: Manganese. Cr: Chromium, V: Vanadium, Mo: Molyb-denum, Cu: Cupper, and N: Nickel
) According to an embodiment herein, the percentage of various elements in the flange (I-7) beam is provided in Table 3.
A: Carbon equivalent value is calculated by following equation
According to an embodiment herein, the percentage weight of specimen is according to melted chemical composition provided in Table 4.
According to an embodiment herein, yield stress, tensile strength, and percent elongation of the flange (I-7) beam are according to Table 5. The specimen undergone bending test (according to Table 5) is free from any crack, break and other defects.
APercent elongation is calculated using L0 and following equation: 5.65√S0L0
According to an embodiment herein, the impact test is performed according to national standard 769-1.
According to an embodiment herein, the method of calculating percentage of ingredients complies with Iran national standard number 10979.
According to an embodiment herein, sampling for chemical test complies with Iran national standard no. 9376. When wet chemistry methods are applied, sampling is according to related instructions and methods.
According to an embodiment herein, for performing tensile and bending test, each flange (I-7) beam bundle is sampled according to Table 6.
According to an embodiment herein, place and position of the flange (I-7) beam specimens are according to Iran national standard no. 491.
According to an embodiment herein, tensile test and bending test of the flange (I-7) beam complies with Iran national standard number 10272 and Iran national standard number 1016 respectively.
According to an embodiment herein, test specimen of the flange (I-7) beam is measured using exact measurement devices in terms of dimensions and sizes evaluated according to Table 1 and the following Table 7.
According to an embodiment herein, the weight of the flange (I-7) beam specimen is calculated based on the exact length of the specimen. The weight deviated from nominal values is calculated as follows:
Percentage of deviation from weight=W1−(WL1)/W1×100 (1)
When considering an individual flange (I-7) beam, W1 represents weight of the test specimen in Kilograms (Kg). W represents weight of 1 meter length flange (I-7) beam according to Table 1, and L1 represents length of the specimen in meter (minimum=30 mm).
When considering a bundle or set of the flange (I-7) beams, W1 represents weight of the bundle or set in Kilograms (Kg), W represents weight of 1 meter length flange (I-7) beam according to Table 1, and L1 represents sum of length of beams in bundle or length in meters.
According to an embodiment herein, the surface of the flange (I-7) beam is flat and according to rolled beam standards. The flange (I-7) beam is free from defects such as crack, delamination, tear, non-metallic inclusion, and fold. The end of the flange (I-7) beam is free from delamination.
According to an embodiment herein, slight defects on the surface of the flange (I-7) beam is removed by employing grinding process or other suitable techniques. The thickness of the grinded parts is made to comply with the above mentioned tolerance values. Further, the repaired parts are casted completely such that the border between the repaired part and rolled surface is flat and smooth.
According to an embodiment herein, all the manufactured flange (I-7) beams are evaluated according to test results of the specimen based on values provided in Table 8.
According to an embodiment herein, the manufacturer of the flange (I-7) beam implements the quality control systems to guarantee specifications mentioned in issued certificate and test results of the specimen according to Table 8.
When the dimensions, sizes, and parameters of the manufactured flange (I-7) beam does not match with the above mentioned values, a rechecking is performed before transporting the flange (I-7) beams to the construction site.
When the weight of the flange (I-7) beam specimen does not match with the proposed weight standards, two specimens of other beams from the same bundle is taken and weighed. Further, an evolution is performed by comparing the weights with standard weights and new results are recorded.
When the appearance results of the manufactured flange (I-7) beam specimen does not match with the proposed appearance standards, the flange (I-7) beam is rejected.
When the results of the mechanical test do not comply with the proposed flange (I-7) beam standards, a resampling of the specimen is performed. The number of samples considered are 2 times more than required samples. When the new results of the mechanical test comply with the proposed flange (I-7) beam standards, previous results are omitted.
According to an embodiment herein, the flange (I-7) beam is rejected when the new results of the mechanical test do not comply with the proposed flange (I-7) beam standards.
According to an embodiment herein, a retest is performed on the flange (I-7) beam specimen, when a potential error in occurred in the initial test processes.
According to an embodiment herein, a retest is performed on the flange (I-7) beam specimen, when there are defects on the surface of the flange (I-7) beam.
According to an embodiment herein, a retest is performed on the flange (I-7) beam, when the distance between rupture and the closest mark of effective length of the flange (I-7) beam is less than one third of effective length and an elongation does not comply with the proposed standards.
According to an embodiment herein, the bundles of the flange (I-7) beam comprises a plate of specifications along with information such as bundle number, identifier, bundle weight (Kg), melt number/lot, name or brand and standard sign.
According to an embodiment herein, marks are embossed on the flange (I-7) beams at a minimum distance of 2 m intervals. For example. ‘Name/brand+identifier+semi light weight I7’ represents a mark on the flange (I-7) beam.
According to an embodiment herein, a technical certificate of each manufactured flange (I-7) beam comprises information related to date of issue, certificate number, beam identifier, bundle number, melt number/lot, percentage of ingredients, mechanical features, beam length, number of bundles, and bundle weight and consignment weight of the flange (I-7) beam.
According to an embodiment herein, an identifier of the flange (I-7) beam 100 comprises an abbreviation, a beam number and a minimum yield strength of steel in N/mm2. For example, A (I-7) beam with a beam number 16 and minimum steel yield strength of 275 N/mm2 is indicated as I-7-16-275.
According to an embodiment herein, the nominal dimensions, sizes and static parameters of the flange (I-7) beam 100 are provided in Table 1.
According to an embodiment herein, the height (h) of the flange (I-7) beam 100 is measured on a central line of the web thickness (s). The thickness (s) of the web is measured at central point of the web 101 after the beam height (h). The thickness (t) of the flange is measured at one fourth of a distance from the edge of the flange. The tolerance values of the beam height (h), flange width (b), web thickness (s), and flange thickness (t) of the flange (I-7) beam 100 are provided in Table 2.
According to an embodiment herein, the maximum weight tolerance of the flange (I-7) beam 100 is equal to ±4% of the normal weight of the flange (I-7) beam 100. The weight deviation is equal to a difference between bundle/piece true weight and computational weight of the flange (I-7) beam 100.
According to an embodiment herein, the weight values shown in Table 1 are calculated based on a density of steel which is equal to 7850/m3.
According to an embodiment herein, the flange (I-7) beam is made up of a steel alloy comprising carbon (C), manganese (Mn), silica (Si), phosphorus (P), sulfur (S), a nitrogen (N), a cupper (Cu), and a Carbonequivalent (Ceq).
Carbonxequivalent(Ceq)=(C+Mn)/6(Cr+V+Mo)/5+(Cu+Ni)/15 (1)
Where C: Carbon, Mn: Manganese, Cr: Chromium, V: Vanadium, Mo: Molyb-denum. Cu: Cupper, and N: Nickel
According to an embodiment herein, the percentage of various elements in the flange (I-7) beam is provided in Table 3.
A: Carbon equivalent value is calculated by following equation
According to an embodiment herein, the percentage weight of specimen is according to melted chemical composition provided in Table 4.
According to an embodiment herein, a yield stress, a tensile strength, and a percent elongation of the flange (I-7) beam 100 are according to Table 5. The specimen undergone bending test (according to Table 5) is free from any crack, break and other defects.
APercent elongation is calculated using L0 and following equation: 5.65√S0L0
According to an embodiment herein, the impact test is performed according to national standard 769-1.
According to an embodiment herein, the method of calculating percentage of ingredients complies with Iran national standard number 10979.
According to an embodiment herein, a sampling for chemical test complies with Iran national standard no. 9376. When the wet chemistry methods are applied, a sampling is according to the related instructions and methods.
According to an embodiment herein, for performing a tensile and bending test, each flange (I-7) beam bundle is sampled according to Table 6.
According to an embodiment herein, a place and a position of the flange (I-7) beam 100 specimens are made to comply with the Iran national standard no. 491.
According to an embodiment herein, a tensile test and a bending test of the flange (I-7) beam complies with the Iran national standard number 10272 and Iran national standard number 1016 respectively.
According to an embodiment herein, a test specimen of the flange (I-7) beam is measured using the exact measurement devices in terms of dimensions and sizes evaluated according to Table 1 and the following Table 7.
According to an embodiment herein, the weight of the flange (I-7) beam 100 specimen is calculated based on the exact length of the specimen. The weight deviated from nominal values is calculated as follows:
Percentage of deviation from weight=W1−(WL1)/W1×100 (1)
Wherein, for an individual flange (I-7) beam, W1 represents weight of the test specimen in Kilograms (Kg), W represents weight of 1 meter length flange (I-7) beam according to Table 1, and L1 represents length of the specimen in meter (minimum=30 mm).
For a bundle or set of the flange (I-7) beams, W1 represents weight of the bundle or set in Kilograms (Kg). W represents weight of 1 meter length flange (I-7) beam according to Table 1, and L1 represents sum of length of beams in bundle or length in meters.
According to an embodiment herein, the surface of the flange (I-7) beam 100 is flat and complies with the rolled beam standards. The flange (I-7) beam 100 is free from defects such as crack, delamination, tear, non-metallic inclusion, and fold. The end of the flange (I-7) beam 100 is free from delamination.
According to an embodiment herein, the minimal or slight defects on the surface of the flange (I-7) beam 100 is removed by employing a grinding process or other suitable techniques. The thickness of the grinded parts complies with the above mentioned tolerance values. Further, the repaired parts are casted completely such that the border between the repaired part and rolled surface is flat and smooth.
According to an embodiment herein, all the manufactured flange (I-7) beams are evaluated according to test results of the specimen based on values provided in Table 8.
According to an embodiment herein, the manufacturer of the flange (I-7) beam 100 implements quality control systems to guarantee specifications mentioned in issued certificate and test results of the specimen disclosed in Table 8.
When the dimensions, sizes, and parameters of the manufactured flange (I-7) beam 100 does not match with the above mentioned values, a rechecking is performed before transporting the flange (I-7) beams to the construction site.
When the weight of the flange (I-7) beam 100 specimen does not match with the proposed weight standards, two specimens of other beams from the same bundle is taken and weighed. Further, an evolution is performed by comparing the weights with standard weights and new results are recorded.
When the appearance results of the manufactured flange (I-7) beam 100 specimen does not match with the proposed appearance standards, the flange (I-7) beam is rejected.
When the results of the mechanical test do not comply with the proposed flange (I-7) beam 100 standards, a resampling of the specimen is performed. The number of samples considered are 2 times more than required samples. When the new results of the mechanical test comply with the proposed flange (I-7) beam 100 standards, the previous results are omitted.
According to an embodiment herein, the flange (I-7) beam 100 is rejected when the new results of the mechanical test does not comply with the proposed flange (I-7) beam 100 standards.
According to an embodiment herein, a retest is performed on the flange (I-7) beam 100 specimen, when a potential error in occurred in the initial test processes.
According to an embodiment herein, a retest is performed on the flange (I-7) beam 100 specimen, when there are defects on the surface of the flange (I-7) beam 100.
According to an embodiment herein, a retest is performed on the flange (I-7) beam, when the distance between rupture and the closest mark of effective length of the flange (I-7) beam is less than one third of effective length and elongation does not comply with the proposed standards.
According to an embodiment herein, the bundles of the flange (I-7) beam comprises a plate of specifications along with information such as bundle number, identifier, bundle weight (Kg), melt number/lot, name or brand and standard sign.
According to an embodiment herein, the marks are embossed on the flange (I-7) beams at a minimum distance of 2 m intervals. For example, ‘Name/brand+identifier+semi light weight I7’ represents a mark on the flange (I-7) beam 100.
According to an embodiment herein, a technical certificate of each manufactured flange (I-7) beam 100) comprises an information related to date of issue, certificate number, a beam identifier, a bundle number, a melt number/lot, a percentage of ingredients, mechanical features, a beam length, a number of bundles, and bundle weight and consignment weight of the flange (I-7) beam 100.
According to an embodiment herein, the ordered effective length (L) of a section in the flange (I-7) beam is provided according to tolerance values provided in Table 9.
According to an embodiment herein, the maximum allowable tilt of transverse shear 301 of the flange (I-7) beam in relation to height (h) is provided in Table 10.
According to an embodiment herein, the maximum allowable tilt of transverse shear 301 of the flange (I-7) beam in relation to width (b) is provided in Table 11.
According to an embodiment herein, the maximum allowable flange tilt (k+k1) of the flange (I-7) beam is provided in table 12.
m=|b1−b2|/2 (2)
where b1 represents a distance between the perpendicular axis and the left edge of the flange, b2 represents a distance between the perpendicular axis and the right edge of the flange.
According to an embodiment herein, asymmetry of the flanges 102 and 103 with respect to the web 101 are provided in Table 13.
According to an embodiment herein, the allowable tolerance of deviation from straightness in the flange (I-7) beam is provided in Table 14.
According to an embodiment herein, the allowable web curvature of the flange (I-7) beam is provided in Table 15.
The steel ingot pieces are placed into a furnace. According to an embodiment herein, the furnace temperature is maintained at 1350° C. (802) and the capacity of the furnace is 40 tonnes per hour. Due to high temperature, the steel alloy of the ingot pieces is melted. Later, the pieces are passed through a rolling assembly. The rolling assembly reduces the thickness of the steel pieces to a desired level and ensures the uniform thickness along the entire length of the steel pieces (803).
According to an embodiment herein, the rolling assembly comprises primary rolling stands, middle rolling stands and final rolling stands.
After the rolling process, the steel pieces are cut into custom sizes of using a plurality of saws (804). Finally, the hot flange (I-7) beams are passed through a cooling bed and a straightener to form the semi lightweight, medium flange (I-7) beams (805).
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.
The embodiments herein claims the priority of the U.S. Provisional patent application with Ser. No. 62/127,297 filed on Mar. 3, 2015 and the contents of which is incorporated in entirety as reference herein.
Number | Date | Country | |
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62127297 | Mar 2015 | US |