Wear-resistant high-strength roll-formed components

Abstract

A method of forming a component having a cross-section with a bend radius includes providing a work-piece blank from press-hardened steel (PHS). The method also includes austenitizing the work-piece blank in a furnace via heating the strip of sheet metal to achieve therein an austenite microstructure, including soaking the work-piece blank for a predetermined amount of time. The method additionally includes quenching the austenitized work-piece blank to achieve therein a martensitic matrix microstructure with dispersed chromium-enriched carbide. The method also includes roll-forming the austenitized and quenched work-piece blank to generate the cross-section and the bend radius. The method may further include locally heating the bend radius area during the roll-forming of the cross-section to reduce an amount of chromium-enriched carbide in the martensitic matrix microstructure inside the bend radius area relative to the microstructure outside the bend, and thereby generating the component having high strength, ductility, and wear resistance.

What is claimed is: 
     
         1 . A method of forming a component having a cross-section having a bend characterized by a bend radius, the method comprising:
 providing a work-piece blank from press-hardened steel (PHS);   austenitizing the work-piece blank in a furnace via heating the work-piece blank to achieve therein an austenite microstructure, including soaking the strip of PHS for a predetermined amount of time;   quenching the austenitized work-piece blank to achieve therein a martensitic matrix microstructure with dispersed chromium-enriched carbide; and   roll-forming the austenitized and quenched work-piece blank via at least one set of rolls to generate the cross-section having the bend radius.   
     
     
         2 . The method of forming the component of  claim 1 , locally heating an area of the bend radius during the roll-forming of the cross-section to reduce an amount of chromium-enriched carbide in the martensitic matrix microstructure inside the bend radius relative to the martensitic matrix microstructure outside the bend radius, and thereby generating the component having high strength, ductility, and wear resistance. 
     
     
         3 . The method of forming the component of  claim 1 , wherein the predetermined amount of time is in a range of 1-1000 seconds. 
     
     
         4 . The method of forming the component of  claim 1 , wherein the quenching is performed at a rate greater than 10° C. per second. 
     
     
         5 . The method of forming the component of  claim 1 , wherein the cross-section has a 1:1 ratio of material thickness to the bend radius without cracks or tears. 
     
     
         6 . The method of forming the component of  claim 1 , wherein locally heating the austenitized and quenched work-piece blank is performed via one of a laser, a microwave, and an infrared device during the roll-forming. 
     
     
         7 . The method of forming the component of  claim 1 , wherein the PHS of the work-piece blank includes carbon (C) in a range of 0.05-0.45% by weight, manganese (Mn) in a range of 0-4.5% by weight, chromium (Cr) in a range of 0.5-6% by weight, and silicon (Si) in a range of 0.5-2.5% by weight. 
     
     
         8 . The method of forming the component of  claim 1 , wherein an amount of chromium in the chromium-enriched carbide is greater than 2% by weight, and wherein particles of the chromium-enriched carbide have a diameter in a range of 5 nm-1.5 μm. 
     
     
         9 . The method of forming the component of  claim 1 , wherein the martensitic matrix microstructure with dispersed chromium-enriched carbide includes:
 martensite (with optional austenite at less than 10% by volume and optional ferrite at less than 5% by volume) at greater than 85% by volume; and   chromium-enriched carbide in a range of 0.2-10% by volume.   
     
     
         10 . The method of forming the component of  claim 1 , wherein the austenitized and quenched work-piece blank has a tensile strength in a range of 1000-2000 MPa. 
     
     
         11 . A roll-formed high strength, ductility, and wear resistant component comprising:
 a cross-section having a bend characterized by a bend radius roll-formed from austenitized and quenched work-piece blank from a press-hardened steel (PHS) having a martensitic matrix microstructure with dispersed chromium-enriched carbide;   wherein, relative to the martensitic matrix microstructure outside the bend radius, the martensitic matrix microstructure in the bend radius has a reduced amount of the chromium-enriched carbide.   
     
     
         12 . The component of  claim 11 , wherein the cross-section has a 1:1 ratio of material thickness to the bend radius without cracks or tears. 
     
     
         13 . The component of  claim 11 , wherein the PHS of the work-piece blank includes carbon (C) in a range of 0.05-0.45% by weight, manganese (Mn) in a range of 0-4.5% by weight, chromium (Cr) in a range of 0.5-6% by weight, and silicon (Si) in a range of 0.5-2.5% by weight. 
     
     
         14 . The component of  claim 11 , wherein an amount of chromium in the chromium-enriched carbide is greater than 2% by weight. 
     
     
         15 . The component of  claim 14 , wherein particles of the chromium-enriched carbide have a diameter in a range of 5 nm-1.5 μm. 
     
     
         16 . The component of  claim 11 , wherein the martensitic matrix microstructure with dispersed carbide includes:
 martensite (with optional austenite at less than 10% by volume and optional ferrite at less than 5% by volume) at greater than 85% by volume; and   chromium-enriched carbide in a range of 0.2-10% by volume.   
     
     
         17 . The component of  claim 11 , wherein the austenitized and quenched work-piece blank from has a tensile strength in a range of 1000-2000 MPa. 
     
     
         18 . A method of forming a structural component including a cross-section having a bend characterized by a bend radius, the method comprising:
 providing a work-piece blank from press-hardened steel (PHS) having carbide enriched with an amount of chromium greater than 2% by weight;   austenitizing the work-piece blank in a furnace via heating the strip of sheet metal to achieve therein an austenite microstructure, including soaking the work-piece blank for 200-500 seconds;   quenching the austenitized work-piece blank at a rate greater than 10° C. per second to achieve therein a martensitic matrix microstructure with dispersed chromium-enriched carbide to achieve ultimate tensile strength thereof in a range of 1000-2000 MPa;   roll-forming the austenitized and quenched work-piece blank via at least one set of rolls to generate the cross-section including the bend radius; and   locally heating an area of the bend radius during the roll-forming of the cross-section to reduce an amount of the chromium-enriched carbide in the martensitic matrix microstructure inside the bend radius area relative to the martensitic matrix microstructure outside the bend radius, and thereby generating the structural component having high strength, ductility, and wear resistance.   
     
     
         19 . The method of forming the structural component of  claim 18 , wherein the PHS of the work-piece blank includes carbon (C) in a range of 0.05-0.45% by weight, manganese (Mn) in a range of 0-4.5% by weight, chromium (Cr) in a range of 0.5-6% by weight, and silicon (Si) in a range of 0.5-2.5% by weight. 
     
     
         20 . The method of forming the structural component of  claim 18 , wherein the martensitic matrix microstructure with dispersed chromium-enriched carbide includes:
 martensite (with optional austenite at less than 10% by volume and optional ferrite at less than 5% by volume) at greater than 85% by volume; and   chromium-enriched carbide in a range of 0.2-10% by volume.