HIGH STRENGTH STICK ELECTRODE

Abstract

A shielded metal arc welding electrode for depositing a high strength weld metal bead on a workpiece which satisfies the strength requirements under America Welding Society A5.5 standard's E11018M classification with no chromium added to the composition of the electrode.

Description

BRIEF DESCRIPTION OF DRAWINGS

The advantages, nature and various additional features of the invention will appear more fully upon consideration of the illustrative embodiment of the invention which is schematically set forth in the figures, in which:

FIG. 1A is a partial cross-sectional view illustrating a test workpiece, in accordance with the first aspect of the invention, when using a cold plate with low heat input to produce a high cooling rate in the deposited weld metal;

FIG. 1B is a view similar to FIG. 1A wherein the test workpiece is preheated and a high welding energy is used to produce a low cooling rate for the weld metal deposited by an electrode;

FIG. 2 is a graph of the carbon equivalent related to yield strength of the weld metal for several electrodes used to perform the two tests conducted on electrodes constructed in accordance with either aspect of the present invention showing the effect of reducing the carbon equivalent, a parameter that reduces the sensitivity of the weld metal to cooling rate; and

FIG. 3 is a cross-section of an embodiment of an electrode according to an embodiment of the second aspect of the present invention.

Claims

1. A welding electrode used for high strength welding, wherein the electrode comprises: at least manganese, molybdenum, nickel, and carbon,wherein the welding electrode provides an undiluted weld deposit having no more than 0.20% by weight of chromium and having an ultimate tensile strength of at least 110 ksi and a 0.2% yield strength in the range of 85 to 125 ksi, when welded with a heat input in the range of about 30 KJ/in to about 60 KJ/in.

2. The welding electrode of claim 1, wherein the yield strength is in the range of 98 to 110 ksi.

3. The welding electrode of claim 1, wherein the welding electrode provides no more than 0.10% by weight of chromium in the weld deposit.

4. The welding electrode of claim 1 wherein the welding electrode provides no more than 0.06% by weight of chromium in the weld deposit.

5. The welding electrode of claim 1, wherein the electrode comprises a core wire and a coating surrounding the core wire.

6. The welding electrode of claim 1, wherein the welding electrode has a diameter of 3/32 inch, ⅛ inch, 5/32 inch or 3/16 inch.

7. The welding electrode of claim 1, wherein the amount of carbon is in the range of 0.8 to 1.5% by weight.

8. The welding electrode of claim 1, wherein the amount of nickel is in the range of 1.2 to 2.0% by weight.

9. The welding electrode of claim 1, wherein the amount of molybdenum is in the range of 0.01 to 0.5% by weight.

10. The welding electrode of claim 1, wherein the amount of manganese is in the range of 1.5 to 2.0% by weight.

11. The welding electrode of claim 3, wherein the coating of the electrode is in the range of 32 to 48% of the electrode.

12. The welding electrode of claim 1, wherein the electrode provides an amount of carbon in the range of 0.04 to 0.06% by weight in the weld deposit.

13. The welding electrode of claim 1, wherein the electrode provides an amount of manganese in the range of 1.5 to 2.25% by weight in the weld deposit.

14. The welding electrode of claim 1, wherein the electrode provides an amount of molybdenum in the range of 0.35 to 0.5% by weight in the weld deposit.

15. The welding electrode of claim 1, wherein the electrode provides an amount of nickel in the range of 1.75 to 2.75% by weight in the weld deposit.

16. A welding electrode used for high strength welding, comprising: a core wire; andan electrode coating surrounding the core wire,wherein at least one of the electrode coating and core wire contains at least manganese, molybdenum, nickel, and carbon, andwherein the welding electrode provides an undiluted weld deposit having no more than 0.20% by weight of chromium and having an ultimate tensile strength of at least 110 ksi and a 0.2% yield strength in the range of 85 to 125 ksi, when welded with a heat input in the range of about 30 KJ/in to about 60 KJ/in.

17. The welding electrode of claim 16, wherein the yield strength is in the range of 98 to 110 ksi.

18. The welding electrode of claim 16, wherein the welding electrode provides no more than 0.10% by weight of chromium in the weld deposit.

19. The welding electrode of claim 16, wherein the welding electrode provides no more than 0.06% by weight of chromium in the weld deposit.

20. The welding electrode of claim 16, wherein the welding electrode has a diameter of 3/32 inch, ⅛ inch, 5/32 inch or 3/16 inch.

21. The welding electrode of claim 16, wherein the coating contains an amount of carbon in the range of 2.5 to 3.0% by weight of the coating.

22. The welding electrode of claim 16, wherein the coating contains an amount of nickel in the range of 2.75 to 5.0% by weight of the coating.

23. The welding electrode of claim 16, wherein the coating contains an amount of molybdenum in the range of 0.5 to 1.2% by weight of the coating.

24. The welding electrode of claim 16, wherein the coating contains an amount of manganese in the range of 3.0 to 4.5% by weight of the coating.

25. The welding electrode of claim 16, wherein the coating of the electrode is in the range of 32 to 48% of the electrode.

26. The welding electrode of claim 16, wherein the electrode provides an amount of carbon in the range of 0.04 to 0.06% by weight in the weld deposit.

27. The welding electrode of claim 16, wherein the electrode provides an amount of manganese in the range of 1.5 to 2.25% by weight in the weld deposit.

28. The welding electrode of claim 16, wherein the electrode provides an amount of molybdenum in the range of 0.35 to 0.5% by weight in the weld deposit.

29. The welding electrode of claim 16, wherein the electrode provides an amount of nickel in the range of 1.75 to 2.75% by weight in the weld deposit.