Recrystallization, Refinement, and Strengthening Mechanisms For Production Of Advanced High Strength Metal Alloys

Abstract

This disclosure deals with a class of metal alloys with advanced property combinations applicable to metallic sheet production. More specifically, the present application identifies the formation of metal alloys of relatively high strength and ductility and the use of one or more cycles of elevated temperature treatment and cold deformation to produce metallic sheet at reduced thickness with relatively high strength and ductility.

1 . A method comprising:
 a. supplying a metal alloy comprising Fe at a level of 55.0 to 88.0 atomic percent, B at a level of 0.5 to 8.0 atomic percent, Si at a level of 0.5 to 12.0 atomic percent and Mn at a level of 1.0 to 19.0 atomic percent;   b. melting said alloy and solidifying to provide a matrix grain size of 200 nm to 200,000 nm;   c. heating said alloy to form a refined matrix grain size of 50 nm to 5000 nm where the alloy has a yield strength of 200 MPa to 1225 MPa;   d. stressing said alloy that exceeds said yield strength of 200 MPa to 1225 MPa wherein said alloy indicates a tensile strength of 400 MPa to 1825 MPa and an elongation of 1.0% to 59.2%.   
     
     
         2 . The method of  claim 1  wherein, in step (b), borides are formed having a size of 20 nm to 10000 nm. 
     
     
         3 . The method of  claim 1 , wherein in step (c), precipitations are formed having a size of 1 nm to 200 nm and borides of 20 nm to 10000 nm in size are present. 
     
     
         4 . The method of  claim 1 , wherein in step (d), said alloy has refined grain size of 25 nm to 2500 nm, borides of 20 nm to 10000 nm in size and precipitations at 1 nm to 200 nm in size. 
     
     
         5 . The method of  claim 1  wherein said solidified alloy in step (b) has a thickness of 1 mm to 500 mm. 
     
     
         6 . The method of  claim 1  wherein said alloy after heating in step (c) has a thickness of 1 mm to 500 mm. 
     
     
         7 . The method of  claim 1  wherein said alloy in step (d) after stressing has a thickness of 0.1 mm to 25 mm. 
     
     
         8 . The method of  claim 1  wherein said alloy in step (d) is heated to a temperature in the range 700° C. and below the melting point of said alloy wherein said alloy has grains of 100 nm to 50,000 nm, borides of 20 nm to 10000 nm in size, precipitations of 1 nm to 200 nm in size, and said alloy has a yield strength of 200 MPa to 1650 MPa. 
     
     
         9 . The method of  claim 8  wherein said alloy, after heating to a temperature in the range of 700° C. and below the melting point of the alloy, has a thickness of 1 mm to 500 mm. 
     
     
         10 . The method of  claim 8  wherein said alloy is then stressed above yield and forms an alloy having grain sizes of 10 nm to 2500 nm, borides of 20 nm to 10000 nm in size, precipitations of 1 nm to 200 nm in size, indicates a yield strength of 200 MPa to 1650 MPa, tensile strength of 400 MPa to 1825 MPa and an elongation of 1.0% to 59.2%. 
     
     
         11 . The method of  claim 10 , wherein said alloy, after stressing above yield, has a thickness of 0.1 mm to 25 mm. 
     
     
         12 . The method of  claim 1  further including one or more of the following:
 Ni at a level of 0.1 to 9.0 atomic percent; 
 Cr at a level of 0.1 to 19.0 atomic percent; 
 Cu at a level of 0.1 to 6.00 atomic percent; 
 Ti at a level of 0.1 to 1.00 atomic percent; and 
 C at a level of 0.1 to 4.0 atomic percent. 
 
     
     
         13 . The method of  claim 1  wherein said alloy has a melting point in the range of 1000° C. to 1450° C. 
     
     
         14 . The method of  claim 1  wherein said alloy is positioned in a vehicle. 
     
     
         15 . The method of  claim 1  wherein said alloy is positioned in a vehicle. 
     
     
         16 . The method of  claim 10  wherein said alloy is positioned in a vehicle. 
     
     
         17 . The method of  claim 1  wherein said alloy is positioned in one of a drill collar, drill pipe, pipe casing, tool joint, wellhead, compressed gas storage tank or liquefied natural gas canister. 
     
     
         18 . A method comprising:
 a. supplying metal alloy comprising Fe at a level of 55.0 to 88.0 atomic percent, B at a level of 0.5 to 8.0 atomic percent, Si at a level of 0.5 to 12.0 atomic percent and Mn at a level of 1.0 to 19.0 atomic percent, wherein said alloy indicates a yield strength of 200 MPa to 1225 MPa and said alloy has a first thickness;   b. heating said alloy to a temperature in the range 700° C. and below the melting point of said alloy and stressing said alloy wherein said alloy indicates a yield strength of 200 MPa to 1650 MPa, tensile strength of 400 MPa to 1825 MPa and an elongation of 1.0% to 59.2%, and said alloy has a second thickness less than said first thickness.   
     
     
         19 . The method of  claim 18  wherein said alloy in step (a) has a tensile strength of 400 MPa to 1825 MPa and an elongation of 1.0% to 59.2%. 
     
     
         20 . The method of  claim 18  wherein said alloy in step (b) has matrix grain size of 10 nm to 2500 nm, borides of 20 nm to 10000 nm in size and precipitations of 1 nm to 200 nm in size. 
     
     
         21 . The method of  claim 18  wherein said alloy in step (a) has a thickness of 1 mm to 500 mm. 
     
     
         22 . The method of  claim 18  wherein said alloy in step (b) has a thickness of 0.1 mm to 25 mm. 
     
     
         23 . The method of  claim 18  wherein said heating and stressing of said alloy is repeated to further said alloy thickness. 
     
     
         24 . The method of  claim 18  wherein said heating and stressing is repeated 2 to 20 times. 
     
     
         25 . The method of  claim 18  wherein said alloy with said second thickness is positioned in a vehicle. 
     
     
         26 . The method of  claim 18  wherein said alloy is positioned in one of a drill collar, drill pipe, pipe casing, tool joint, wellhead, compressed gas storage tank or liquefied natural gas canister.