Steel rails' joint fishplate made of xy30 steel

Abstract

The present invention relates to a rail clip, an important fitting part, for the railway made of a new steel XY30 which is one of a high-manganese steel without nickel and which has high strength and high toughness even if it is used in the low-temperature circumstance. The rail clip is characterized in that the rail clip has the shape of a bar with a section of “T” and comprises a working surface, a non-working surface, a mounting surface for bolts and a non-working surface inside a web plate; the two working surfaces of a upper small surface side and a lower large surface side on the same side of the rail clip come into circular arc point contact with the railroad rail, a small circular arc is provided on the working surface which is on the upper small surface side; the upper small surface side, the lower large surface side and the non-working surface inside the web plate are connected with circular arcs; upper and lower non-working surfaces on the other side of the rail clip are perpendicular to the horizon.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a rail clip, which is an important fitting part for the railway made of a new steel XY30 and one of a high-manganese steel without nickel and having high strength and high toughness even if it is used in the low-temperature circumstance.

DESCRIPTION OF THE RELATED ART

[0002] The rail clip is used to joint railroad rails made of the steel XY30 in the low-temperature circumstance, which is an important fitting part to the railway, so the technical properties are strictly prescribed. The rail clip for the railway is made of steel B7 in accordance with the Railway Standard TB/T2342.1˜4-93 being enacted by the railroad department of the People's Republic of China and entered into force in China in 1993.

[0003] The chemistry composition of the steel B7 is as following:

[0004] C: 0.50˜0.62%, Mn: 0.50˜0.80%, Si: 0.15˜0.35%, P:<0.045%, S<0.050%.

[0005] The mechanical properties of the steel B7 after heat treatment are as following:

[0006] Tensile strength σb≧785 Mpa, yield strength σb≧520 Mpa, percentage elongation δs≧9%, percentage reduction of area ≧20%, Brinell hardness HB227˜399, and being in good condition under a cold bending angle of 30°.

[0007] The mechanical properties of the rail clip for the technical acceptance check under the normal temperature prescribed by the US AREMA Standard are as following.

[0008] Tensile strength σb≧690 Mpa, yield strength σs≧480 Mpa, percentage elongation δs≧12%, percentage reduction of area ≧28%, and being in good condition under a cold bending angle of d=3a, 180°.

[0009] It has been proved with the application over a long period of time that the steel B7 is only suitable for the normal temperature to −20° C. The steel B7 is apt to rupture when it is used under a low temperature, so that the railway is adversely affected due to rupture failures which are often occurring at trunk railways since there is a great deal of temperature differences among provinces. Recently the steel B7 no longer satisfies the requirement necessary for the rail clip since the mechanical properties of the rail clip should be improved to match the increasing speed of the railway communication.

SUMMARY OF THE INVENTION

[0010] The object of the present invention is to provide a rail clip used for railway and made of the steel XY30, the rail clip has improved low temperature properties, e.g. high strength and toughness under a low temperature.

[0011] In order to achieve the above object, the present invention provides a steel which is based on a high manganese steel into which appropriate amount of Mo (molybdenum) and V (vanadium), Nb (Niobium), Al (Aluminum) and rare earth element in minute quantities are added.

[0012] The rail clip or joint bar made of the steel XY30 according to present invention is as following.

[0013] The rail clip according to present invention is characterized in that the rail clip is made of the steel XY30, the chemistry composition of the steel XY30 is as following (%): C: 0.28˜0.34, Mn: 1.30˜1.50, Si: 0.15˜0.35, P<0.030, S<0.030, Mo: 0.25˜0.35, V: 0.10˜0.25, Al: 0.015, Nb: 0.05˜0.10, Re: 0.040˜0.20, Cu<0.20; the rail clip has a shape of a bar with a section of “T”, the rail clip comprising: a working surface, a non-working surface, a mounting surface for mounting bolts and a non-working surface inside a web plate; a small circular arc is provided on the working surface which is on an upper small surface side on the same side of the rail clip; the upper small surface, a lower large surface and the non-working surface inside the web plate are connected with circular arcs; upper and lower non-working surfaces on the other side of the rail clip are perpendicular to the horizon.

[0014] The rail clip being an important fitting part for the railway made of the steel XY30 and used for rails according to present invention is designed for the rails of the high-speed railway. The strength and toughness of the rail clip of the present invention under a low temperature are increased since the rail clip is made of the steel XY30. Through the detection and application test of the national research & analysis center of materials of China, the rail clip can be used under the temperature of −60˜30° C. with high strength and toughness and without crack and rupture, and the service life of the rail clip is increased by 1.5˜2 times. Therefore, the rail clip is adapted to rails used in the developing high-speed railway.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a schematic view showing the working surface structure of the rail clip made of steel XY30 for railroad rails according to present invention; where 1—a working surface of the rail clip for railroad rails; 2—a non-working surface; 3—a working surface for bolts; 4—a non-working surface inside a web plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As shown in the FIG. 1, the rail clip made of steel XY30 for railroad rails according to present invention is achieved as following, the chemistry composition of the steel XY30 is as following (%): C: 0.28˜0.34, Mn: 1.30˜1.50, Si: 0.15˜0.35, P<0.030, S<0.030, Mo: 0.25˜0.35, V: 0.10˜0.25, Al: 0.015, Nb: 0.05˜0.10, Re: 0.040˜0.20, Cu<0.20. The rail clip has a shape of a bar with a section of “T”, the rail clip comprising: a working surface 1, a non-working surface 2, a mounting surface for bolts 3 and a non-working surface inside a web plate 4. The two working surfaces 1 on an upper small surface side and a lower large surface side on the same side of the rail clip come into circular arc point contact with the railroad rail. The contacting circular arcs of the working surfaces of the upper small surface have a radius of R2═R19.05 mm and a radius of R1═R9.526 mm, respectively, while the contacting circular arcs of the working surfaces of the lower large surface have a radius of R6═R355.6 mm and a radius of R5═R10.05 mm, respectively. The connecting circular arc connecting the upper small surface with the non-working surface inside the web plate 4 has a radius of R3═R25.4 mm, the connecting circular arc connecting the lower large surface with the non-working surface inside the web plate 4 have a radius of R4═R14.287 mm. The upper and lower non-working surfaces 2 on the other side of the rail clip are perpendicular to the horizon, the upper non-working surface is projected from the mounting surface for bolts 3 with H1=15.875 mm, the lower non-working surface is projected from the mounting surface for bolts 3 with H2=22.225 mm. A small circular arc is provided at the center along the length of the working surface of the upper small surface (that is, along the direction perpendicular to the cross section shown in the FIG. 1). The small circular arc has a width of 54.9 mm along the length of the working surfaces of the upper small surface, and a radius of R101.6 mm perpendicular to the working surfaces of the upper small surface, a depth of 1.190 mm with respect to the working surfaces of the upper small surface. The small circular arc is extended from the center of the circular arc corresponding to the R1, to its point of tangency where the small circular arc is tangental to the circular arc corresponding to the R3, via the circular arc corresponding to the R2. The small circular arc is located at the gap between the joint ends of two rails when the rails are installed, so that the shearing force of the cross section can be eliminated when the joint ends of two rails are bend downwards.

Claims

1. A rail clip for railroad rails is characterized in that the rail clip is made of the steel XY30, the chemistry composition of the steel XY30 is as following (%): C: 0.28˜0.34, Mn: 1.30˜1.50, Si: 0.15˜0.35, P<0.030, S<0.030, Mo: 0.25˜0.35, V: 0.10˜0.25, Al: 0.015, Nb: 0.05˜0.10, Re: 0.040˜0.20, Cu<0.20; the rail clip has a shape of a bar with a section of “T”, the rail clip comprising: a working surface, a non-working surface, a mounting surface for mounting bolts and a non-working surface inside a web plate; the two working surfaces on an upper small surface side and a lower large surface side on the same side of the rail clip come into circular arc point contact with the railroad rail, a small circular arc is provided on the working surface which is on the upper small surface side; the upper small surface, the lower large surface and the non-working surface inside the web plate are connected with circular arcs.

2. The rail clip for railroad rails as claimed in the claim 1 is characterized in that the contacting circular arcs of the working surfaces of the upper small surface have a radius of R2=19.05 mm and a radius of R1═R9.526 mm, respectively, while the contacting circular arcs of the working surfaces of the lower large surface have a radius of R6═R355.6 mm and a radius of R5═R10.05 mm, respectively, the connecting circular arc connecting the upper small surface with the non-working surface inside the web plate 4 has a radius of R3═R 25.4 mm, the connecting circular arc connecting the lower large surface with the non-working surface inside the web plate 4 have a radius of R4═R14.287 mm; the upper and lower non-working surfaces on the other side of the rail clip are perpendicular to the horizon, the upper non-working surface is projected from the mounting surface for mounting bolts with H1=15.875 mm, the lower non-working surface is projected from the mounting surface for mounting bolts with H2=22.225 mm.

3. The rail clip for railroad rails as claimed in the claim 1 is characterized in that a small circular arc is provided at the center along the length of the working surfaces of the upper small surface, the small circular arc has a width of 54.9 mm along the length of the working surface of the upper small surface, and a radius of R101.6 mm perpendicular to the working surfaces of the upper small surface, a depth of 1.190 mm with respect to the working surfaces of the upper small surface, the small circular arc is extended from the center of the circular arc corresponding to the R1, to its point of tangency where the small circular arc is tangental to the circular arc corresponding to the R3, via the circular arc corresponding to the R2.

4. The rail clip for railroad rails as claimed in the claim 1 is characterized in that upper and lower non-working surfaces on the other side of the rail clip are perpendicular to the horizon.