Correlating Precipitates and Texture Formation on Batch and Continuous Annealed Rolled Interstitial Free Steels

GLADYS CHARCA RAMOS; MIKE STOUT; RAUL EDUARDO BOLMARO

Rio de Janeiro

Congreso; 17th International Microscopy Congress; 2010

IMC

Automotive, beverage and appliance industries, among others, have used deep drawing processing for many years to form parts from a variety of sheet metals. The formability of a sheet can be best characterized through the R-value which, on BCC Fe alloys, strongly depends on the development of a severe {111} recrystallization texture, what is achieved by lowering the interstitial carbon and nitrogen contents and adding stabilizing elements such as Ti. In this kind of steel, Ti scavenges C and N atoms out of the solution, forming precipitates. The times, temperatures and reductions of thermo mechanical steelmaking processes affect the size, shape and distribution of precipitates, which in turn influence the final recrystallization texture evolution.In this investigation, we study how, after rolling, continuous and batch annealing determine the kind, size and dispersion of precipitates in interstitial free steels and the relationship between the microstructures and texture. The material used in this study was an extra low-carbon, hot-rolled steel, with 0.003% C, 0.005% Si, 0.001% Nb, 0.145% Mn, 0.018% Cu, 0.005% Sn, 0.001% V, 0.013% P, 0.009% Ni, 0.038% Al, 0.066% Ti, 0.016% Cr, 0.0001% B, 0.007% S and 0.0017%.