Grain boundary cohesion enhanced sulfide stress cracking (ssc)-resistant steel alloys

Abstract

Alloys, processes for preparing the alloys, and articles including the alloys are provided. The alloys can include, by weight, about 0% to about 8% nickel, about 1% to about 6% tungsten, about 1% to about 4% copper, about 0.1% to about 2% chromium, about 0.01% to about 1% vanadium, about 0.01% to about 0.5% carbon, about 0.01% to about 0.1% titanium, about 0.001% to about 0.01% boron, about 0% to about 1% silicon, and about 0% to about 0.1% calcium, the balance essentially iron and incidental elements and impurities.

What is claimed is: 
     
         1 . An alloy comprising, by weight, about 0% to about 8% nickel, about 1% to about 6% tungsten, about 1% to about 4% copper, about 0.1% to about 2% chromium, about 0.01% to about 1% vanadium, about 0.01% to about 0.5% carbon, about 0.01% to about 0.1% titanium, about 0.001% to about 0.01% boron, about 0% to about 1% silicon, and about 0% to about 0.1% calcium, the balance essentially iron and incidental elements and impurities. 
     
     
         2 . The alloy of  claim 1  comprising, by weight, about 6% to about 7% nickel, about 3.5% to about 4.5% tungsten, about 2% to about 3% copper, about 0.1% to about 1% chromium, about 0.01% to about 0.2% vanadium, about 0.01% to about 0.2% carbon, about 0.01% to about 0.05% titanium, and about 0.001% to about 0.002% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         3 . The alloy of  claim 1 , wherein the alloy has a calculated Δ2γ value of less than or equal to −2 J/m 2 . 
     
     
         4 . The alloy of  claim 1 , wherein the alloy has a yield strength of greater than or equal to 965 MPa (140 ksi), measured according to ASTM E8. 
     
     
         5 . The alloy of  claim 1 , wherein the alloy has a sulfide stress corrosion cracking toughness (K1SSC) value of greater than or equal to 44 MPa*m 1/2  (40 ksi*in 1/2 ). 
     
     
         6 . The alloy of  claim 1 , wherein the alloy has an M 2 C phase fraction of 0.01 to 0.015, wherein M is selected from the group consisting of W, Cr, V, and Ti, or any combination thereof 
     
     
         7 . The alloy of  claim 1 , wherein the alloy has a body centered cubic copper phase fraction of 
     
     
         0 . 025 to 0.035. 
     
     
         8 . The alloy of  claim 1  comprising about 6.5% nickel. 
     
     
         9 . The alloy of  claim 1  comprising about 4% tungsten. 
     
     
         10 . The alloy of  claim 1  comprising about 2.5% copper. 
     
     
         11 . The alloy of  claim 1  comprising about 0.5% chromium. 
     
     
         12 . The alloy of  claim 1  comprising about 0.1% vanadium. 
     
     
         13 . The alloy of  claim 1  comprising about 0.1% carbon. 
     
     
         14 . The alloy of  claim 1  comprising about 0.02% titanium. 
     
     
         15 . The alloy of  claim 1  comprising about 0.0015% boron. 
     
     
         16 . The alloy of  claim 1  comprising, by weight, about 6.5% nickel, about 4.5% tungsten, about 2.5% copper, about 0.5% chromium, about 0.1% vanadium, about 0.1% carbon, about 0.02% titanium, and about 0.0015% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         17 . A method for producing an alloy comprising:
 preparing a melt that comprises, by weight, about 0% to about 8% nickel, about 1% to about 6% tungsten, about 1% to about 4% copper, about 0.1% to about 2% chromium, about 0.01% to about 1% vanadium, about 0.01% to about 0.5% carbon, about 0.01% to about 0.1% titanium, about 0.001% to about 0.01% boron, about 0% to about 1% silicon, and about 0% to about 0.1% calcium, the balance essentially iron and incidental elements and impurities.   
     
     
         18 . The method of  claim 17 , wherein the melt comprises, by weight, about 6% to about 7% nickel, about 3.5% to about 4.5% tungsten, about 2% to about 3% copper, about 0.1% to about 1% chromium, about 0.01% to about 0.2% vanadium, about 0.01% to about 0.2% carbon, about 0.01% to about 0.05% titanium, and about 0.001% to about 0.002% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         19 . The method of  claim 17 , wherein the melt comprises, by weight, about 6.5% nickel, about 4.5% tungsten, about 2.5% copper, about 0.5% chromium, about 0.1% vanadium, about 0.1% carbon, about 0.02% titanium, and about 0.0015% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         20 . The method of  claim 17 , wherein the alloy has a calculated Δ2γ value of less than or equal to −2 J/m 2 . 
     
     
         21 . The method of  claim 17 , wherein the alloy has a yield strength of greater than or equal to 965 MPa (140 ksi), measured according to ASTM E8. 
     
     
         22 . The method of  claim 17 , wherein the alloy has a sulfide stress corrosion cracking toughness (K1SSC) value of greater than or equal to 44 MPa*m 1/2  (40 ksi*in 1/2 ). 
     
     
         23 . The method of  claim 17 , wherein the alloy has an M 2 C phase fraction of 0.01 to 0.015, wherein M is selected from the group consisting of W, Cr, V, and Ti, or any combination thereof 
     
     
         24 . The method of  claim 17 , wherein the alloy has a body centered cubic copper phase fraction of 0.025 to 0.035. 
     
     
         25 . The method of  claim 17 , wherein the alloy is produced by vacuum melt or air melt practices. 
     
     
         26 . A manufactured article comprising an alloy that comprises, by weight, about 0% to about 8% nickel, about 1% to about 6% tungsten, about 1% to about 4% copper, about 0.1% to about 2% chromium, about 0.01% to about 1% vanadium, about 0.01% to about 0.5% carbon, about 0.01% to about 0.1% titanium, about 0.001% to about 0.01% boron, about 0% to about 1% silicon, and about 0% to about 0.1% calcium, the balance essentially iron and incidental elements and impurities. 
     
     
         27 . The article of  claim 26 , wherein the alloy comprises, by weight, about 6% to about 7% nickel, about 3.5% to about 4.5% tungsten, about 2% to about 3% copper, about 0.1% to about 1% chromium, about 0.01% to about 0.2% vanadium, about 0.01% to about 0.2% carbon, about 0.01% to about 0.05% titanium, and about 0.001% to about 0.002% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         28 . The article of  claim 26 , wherein the alloy comprises, by weight, about 6.5% nickel, about 4.5% tungsten, about 2.5% copper, about 0.5% chromium, about 0.1% vanadium, about 0.1% carbon, about 0.02% titanium, and about 0.0015% boron, the balance essentially iron and incidental elements and impurities. 
     
     
         29 . The article of  claim 26 , wherein the alloy has a calculated Δ2γ value of less than or equal to −2 J/m 2 . 
     
     
         30 . The article of  claim 26 , wherein the alloy has a yield strength of greater than or equal to 965 MPa (140 ksi), measured according to ASTM E8. 
     
     
         31 . The article of  claim 26 , wherein the alloy has a sulfide stress corrosion cracking toughness (K1SSC) value of greater than or equal to 44 MPa*m 1/2  (40 ksi*in 1/2 ). 
     
     
         32 . The article of  claim 26 , wherein the alloy has an M 2 C phase fraction of 0.01 to 0.015, wherein M is selected from the group consisting of W, Cr, V, and Ti, or any combination thereof 
     
     
         33 . The article of  claim 26 , wherein the alloy has a body centered cubic copper phase fraction of 0.025 to 0.035. 
     
     
         34 . The article of  claim 26 , wherein the article is a steel pipe or steel tube.