Micro-alloyed manganese-boron steel

Abstract

A micro-alloyed manganese-boron steel includes about 0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to 0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt. % chromium, molybdenum and nickel, and about 0.01 to 0.06 wt. % aluminum, niobium and titanium. The balance is iron, and the steel is a micro-alloyed material for hot stamping of automotive parts.

1 . A micro-alloyed manganese-boron steel comprising:
 about 0.25 to 0.4 wt. % carbon;   about 0.5 to 2.7 wt. % manganese;   about 0.001 to 0.005 wt. % boron;   about 0.1 to 0.8 wt. % silicon;   about 0.1 to 0.6 wt. % chromium, molybdenum and nickel; and   about 0.01 to 0.06 wt. % aluminum, niobium and titanium;   the balance being iron, and the steel being a micro-alloyed material for hot stamping of automotive parts.   
     
     
         2 . The manganese-boron steel of  claim 1 , further comprising up to about 0.01 wt. % sulfur, vanadium or both. 
     
     
         3 . The manganese-boron steel of  claim 1 , further comprising up to about 0.01 wt. % nitrogen. 
     
     
         4 . The manganese-boron steel of  claim 1 , further comprising up to about 0.03 wt. % phosphorus. 
     
     
         5 . The manganese-boron steel of  claim 1 , wherein the steel is coated with an aluminum silicon coating. 
     
     
         6 . The manganese-boron steel of  claim 5 , wherein the coating comprises AlSi10Fe3. 
     
     
         7 . A hot stamping method comprising:
 forming a hot stamped automotive component, from a micro-alloyed manganese-boron steel blank comprising about 0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to 0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt. % chromium, molybdenum and nickel, about 0.01 to 0.06 wt. % aluminum, niobium and titanium, and a balance of iron, by hot stamping such that the component reaches a minimum yield strength of 1400 MPa at an end of hot stamping.   
     
     
         8 . The method of  claim 7 , wherein the micro-alloyed manganese-boron steel blank further comprises up to about 0.01 wt. % nitrogen. 
     
     
         9 . The method of  claim 7 , wherein the micro-alloyed manganese-boron steel blank further comprises up to about 0.01 wt. % sulfur, vanadium, or both and/or up to about 0.03 wt. % phosphorus. 
     
     
         10 . The method of  claim 7 , wherein at an end of a quenching operation, and prior to baking in a paint oven, the hot stamped component has a minimum tensile strength of about 1800 MPa. 
     
     
         11 . The method of  claim 7 , wherein at an end of a quenching operation, and prior to baking in a paint oven, the hot stamped component has minimum total elongation of about 6%. 
     
     
         12 . The method of  claim 7 , further comprising coating the micro-alloyed manganese-boron steel with an aluminum silicon coating. 
     
     
         13 . The method of  claim 7 , further comprising exposing the hot stamped component to elevated temperatures in a paint baking oven to increase yield strength beyond the 1400 MPa. 
     
     
         14 . The method of  claim 7 , wherein the end of the hot stamping includes releasing the component after quenching. 
     
     
         15 . A hot stamped component comprising:
 a micro-alloyed manganese-boron steel including about 0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to 0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt. % chromium, molybdenum and nickel, and about 0.01 to 0.06 wt. % aluminum, niobium and titanium, the balance being iron, and having a minimum yield strength of at least 1400 MPa.   
     
     
         16 . The hot stamped component of  claim 15 , wherein the component is a body in white automotive part. 
     
     
         17 . The hot stamped component of  claim 15 , wherein the component is a side beam. 
     
     
         18 . The hot stamped component of  claim 15 , wherein the component, at an end of hot stamping, has a minimum tensile strength of about 1800 MPa. 
     
     
         19 . The hot stamped component of  claim 15 , wherein the component, at an end of hot stamping, has a minimum total elongation of about 6%. 
     
     
         20 . The hot stamped component of  claim 15 , wherein the micro-alloyed manganese-boron steel is coated with an aluminum silicon coating.