Non-ridging ferritic chromium alloyed steel

A chromium alloyed ferritic steel comprising:

• ≦0.020% Al, 0.10-0.30% Ti, ≦0.02% C, ≦1.50% Mn, 0.005-0.012% N, ≦1.5% Si, 8-25% Cr, <2.0% Ni, a sub-equilibrium amount of Ti, the ratio of (Ti×N)/Al>0.16, all percentages by weight, the balance Fe and residual elements,
• the steel after being recrystallization annealed having a rm value of ≧1.4 and being substantially free of ridging after forming,
• the annealed steel cold reduced from hot processed steel not previously annealed prior to cold reduction, and
• the hot processed steel formed from a steel deoxidized with deoxidizer consisting essentially of titanium and having an as-cast structure ≧80% equiaxed grains.

A process for making chromium alloyed steel comprising the steps of:

• providing a chromium alloyed ferrous steel melt comprising Ti, N, and Al,
• deoxidizing the melt with a deoxidizer consisting essentially of Ti in an amount of Ti, by weight percentage, satisfying the relationship (Ti×N)/Al>0.14, all by weight percentage,
• casting the melt into a steel having an as-cast structure ≧50% equiaxed grains,
• hot processing the steel,
• descaling the steel,
• cold reducing the steel to final thickness, and
• recrystallization annealing the cold reduced steel wherein the annealed sheet is substantially free of ridging after forming.

A process for making chromium alloyed steel, comprising the steps of:

• providing a steel containing ≦0.013% Al, 0.15-0.25% Ti, ≦0.02% C, ≦1.50 Mn, 0.005-0.012% N, ≦1.5% Si, 8-25% Cr, <2.0% Ni, the ratio of (Ti, ×N)/Al≧0.16 and (Ti/48)/[(C/12)+(N/14)]>1.5, a sub-equilibrium amount of Ti, all percentages by weight, the balance Fe and residual elements,
• casting the melt into a steel having an as-cast structure ≧80% equiaxed grains,
• hot processing the steel into a sheet,
• descaling the sheet,
• cold reducing the sheet to a final thickness without prior annealing, and
• recrystallization annealing the cold reduced sheet wherein the annealed sheet is essentially free of ridging when formed into a part.