Cast steel alloy component having reduced ferrite and enhanced ultimate tensile strength for a vehicle

Abstract

A cast steel alloy for an engine of a vehicle is provided. The cast steel alloy comprises 0.29 to 0.65 weight percent (wt %) carbon, 0.40 to 0.80 wt % silicon, 0.6 to 1.5 wt % manganese, up to 0.03 wt % phosphorus, 0.04 to 0.07 wt % sulfur, 0.8 to 1.4 wt % chromium, 0.2 to 0.6 wt % nickel, 0.15 to 0.55 wt % molybdenum, 0.25 to 2.0 wt % copper, up to 0.03 wt % titanium, 0.07 to 0.17 wt % vanadium, 0.02 to 0.06 wt % aluminum, up to 0.03 wt % nitrogen (N), and 0.01 to 0.06 wt % of at least one of cerium (Ce) and lanthanum. The cast steel alloy has unexpected and unconventional results such as reduced ferrite and enhanced strengths.

1 . A method of casting a steel alloy having reduced ferrite and enhanced ultimate tensile strength for a component of an engine, the method comprising:
 providing a mold of the component, the mold having at least one molded cavity;   melting a steel solution at between 1620 degrees Celsius (° C.) and 1700° C., the steel solution comprising at least one of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), chromium (Cr), nickel (Ni), molybdenum (Mo), copper (Cu), titanium (Ti), vanadium (V), aluminum (Al), and nitrogen (N), defining a raw charge;   adding a master alloy solute to the raw charge at between 1620° C. and 1700° C. to define the steel melt, the steel melt comprising greater than 0.29 weight percent (wt %) C, greater than 0.40 wt % Si, greater than 0.6 wt % Mn, up to 0.03 wt % P, greater than 0.04 wt % S, greater than 0.8 wt % Cr, about 0.2 wt % Ni, greater than 0.15 wt % Mo, greater than 0.25 wt % Cu, up to 0.03 wt % Ti, greater than 0.07 wt % V, greater than 0.02 wt % Al, up to 0.03 wt % N, and 0.01 to 0.06 wt % of at least one of cerium (Ce) and lanthanum (La),   wherein the steel melt has a target composition of 0.35 wt % C, 0.45 wt % Si, 1.0 wt % Mn, up to 0.03 wt % P, 0.06 wt % S, 1.0 wt % Cr, 0.2 wt % Ni, 0.25 wt % Mo, 0.45 wt % Cu, up to 0.03 wt % Ti, 0.1 wt % V, 0.03 wt % Al, 0.03 wt % N, and 0.02 wt % of at least one of Ce and La;   pouring the steel melt in the at least one molded cavity at about 1600° C.;   solidifying the target steel alloy in the at least one molded cavity at about 450° C.; and   separating the target steel alloy from the at least one molded cavity defining a cast steel component having reduced ferrite and enhanced strengths.   
     
     
         2 . The method of  claim 1  wherein the steel melt comprises 0.02 wt % of La and Ce, the steel melt having a La—Ce weight ratio of greater than 2:1. 
     
     
         3 . The method of  claim 1  wherein the steel melt comprises 0.02 wt % of Ce and La, the steel melt having a Ce—La weight ratio of greater than 2:1. 
     
     
         4 . The method of  claim 1  wherein the cast steel component has an ultimate tensile strength of about 840 MPa and about 1100 MPa. 
     
     
         5 . The method of  claim 1  wherein the cast steel component has an elongation percent of between about 7% and about 10%. 
     
     
         6 . The method of  claim 1  wherein the step of separating comprises:
 shaking out the at least one molded cavity from target steel alloy; 
 degating the target steel alloy after the step of shaking out; 
 cleaning the target steel alloy after the step of degating; and 
 inspecting the target steel alloy after the step of cleaning to define the cast steel component. 
 
     
     
         7 . The method of  claim 1  wherein the step of providing comprises:
 making the mold of the component, the mold having a pattern with dimensions identical to the cast steel component. 
 
     
     
         8 . A system for casting a steel alloy having reduced ferrite and enhanced strengths for a component of an engine, the system comprising:
 a molding unit arranged to form a mold of the component, the mold having at least one molded cavity;   a furnace for melting a steel solution and a master alloy solute at between 1620 degrees Celsius (° C.) and 1700° C. to define a steel melt, the steel solution comprising at least one of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), chromium (Cr), nickel (Ni), molybdenum (Mo), copper (Cu), titanium (Ti), vanadium (V), aluminum (Al), and nitrogen (N),   wherein the steel solution comprises greater than 0.29 weight percent (wt %) C, greater than 0.40 wt % Si, greater than 0.6 wt % Mn, up to 0.03 wt % P, greater than 0.04 wt % S, greater than 0.8 wt % Cr, about 0.2 wt % Ni, greater than 0.15 wt % Mo, greater than 0.25 wt % Cu, up to 0.03 wt % Ti, greater than 0.07 wt % V, greater than 0.02 wt % Al, up to 0.03 wt % N, and 0.01 to 0.06 wt % of at least one of cerium (Ce) and lanthanum (La),   wherein the steel melt has a composition of 0.29 to 0.65 weight percent (wt %) carbon, 0.40 to 0.80 wt % silicon, 0.6 to 1.5 wt % manganese, up to 0.03 wt % phosphorus, 0.04 to 0.07 wt % sulfur, 0.8 to 1.4 wt % chromium, 0.2 to 0.6 wt % nickel, 0.15 to 0.55 wt % molybdenum, 0.25 to 2.0 wt % copper, up to 0.03 wt % titanium, 0.07 to 0.17 wt % vanadium, 0.02 to 0.06 wt % aluminum, up to 0.03 wt % nitrogen (N), and 0.01 to 0.06 wt % of at least one of cerium (Ce) and lanthanum;   a pouring mechanism for pouring the steel melt in the at least one molded cavity at about 1600° C.;   a cooling area for solidifying the target steel alloy in the at least one molded cavity at about 450° C.;   a separation unit for separating the target steel alloy from the at least one molded cavity defining a cast steel component having reduced ferrite and enhanced strengths;   a controller in communication with the molding unit, the furnace, the pouring mechanism, and the shakeout unit, the controller configured to control the molding unit, the furnace, the pouring mechanism, and the separation unit; and   a power source configured to power the molding unit, the furnace, the pouring mechanism, the separation unit, and the controller.   
     
     
         9 . The system of  claim 8  wherein the steel melt comprises 0.02 wt % of La and Ce, the steel melt having a La—Ce weight ratio of greater than 2:1. 
     
     
         10 . The system of  claim 8  wherein the steel melt comprises 0.02 wt % of Ce and La, the steel melt having a Ce—La weight ratio of greater than 2:1. 
     
     
         11 . The system of  claim 8  wherein the cast steel component has an ultimate tensile strength of about 840 MPa and about 1100 MPa. 
     
     
         12 . The system of  claim 8  wherein the cast steel component has an elongation percent of between about 7% and about 10%. 
     
     
         13 . The system of  claim 8  wherein the separation unit is arranged to shakeout the at least one molded cavity from target steel alloy, degate the target steel alloy after shaking out the at least one molded cavity, clean the target steel alloy after degating the target steel alloy; and inspect the target steel alloy after the cleaning the target steel alloy, defining the cast steel component. 
     
     
         14 . The system of  claim 8  wherein the steel melt has a target composition of 0.35 wt % C, 0.45 wt % Si, 1.0 wt % Mn, up to 0.03 wt % P, 0.06 wt % S, 1.0 wt % Cr, 0.2 wt % Ni, 0.25 wt % Mo, 0.45 wt % Cu, up to 0.03 wt % Ti, 0.1 wt % V, 0.03 wt % Al, 0.03 wt % N, and 0.02 wt % of at least one of Ce and La; 
     
     
         15 . A cast steel alloy comprising:
 0.29 to 0.65 weight percent (wt %) carbon (C);   0.40 to 0.80 wt % silicon (Si);   0.6 to 1.5 wt % manganese (Mn);   up to 0.03 wt % phosphorus (P);   0.04 to 0.07 wt % sulfur (S);   0.8 to 1.4 wt % chromium (Cr);   0.2 to 0.6 wt % nickel (Ni);   0.15 to 0.55 wt % molybdenum (Mo);   0.25 to 2.0 wt % copper (Cu);   up to 0.03 wt % titanium (Ti);   0.07 to 0.17 wt % vanadium (V);   0.02 to 0.06 wt % aluminum (Al);   up to 0.03 wt % nitrogen (N); and   0.01 to 0.06 wt % of at least one of cerium (Ce) and lanthanum (La).   
     
     
         16 . The cast steel alloy of  claim 15  wherein the cast steel component comprises:0.35 wt % C, 0.45 wt % Si, 1.0 wt % Mn, up to 0.03 wt % P, 0.06 wt % S, 1.0 wt % Cr, 0.2 wt % Ni, 0.25 wt % Mo, 0.45 wt % Cu, up to 0.03 wt % Ti, 0.1 wt % V, 0.03 wt % Al, 0.03 wt % N, and 0.02 wt % of at least one of Ce and La; 
     
     
         17 . The cast steel alloy of  claim 15  wherein the steel alloy has a La—Ce weight ratio of greater than 2:1. 
     
     
         18 . The cast steel alloy of  claim 15  wherein steel alloy has a Ce—La weight ratio of greater than 2:1. 
     
     
         19 . The cast steel alloy of  claim 15  wherein the steel alloy has an ultimate tensile strength of about 840 MPa and about 1100 MPa. 
     
     
         20 . The cast steel alloy of  claim 15  wherein the cast steel alloy is formed of a cast steel component.