BH-IF钢超快速加热退火工艺

Ultra-rapid Heating Annealing Process of BH-IF Steel

研究了不同退火条件对BH-IF钢组织和织构演变及性能的影响.结果表明:随着加热速率的增加,BH-IF钢晶粒得到细化,但并不明显,强度和延伸率提高,再结晶织构仍为典型的管状γ织构;在超快速加热速率条件下,XRD织构分析显示BH-IF钢γ取向纤维织构组分及强度差异缩小,各组分更趋均匀.随保温时间增加,γ取向纤维织构强度增加,因而由其决定的r值(塑性应变比)增加.在超快速加热速率条件下,试样平行于轧向的r0降低,而垂直于轧向的r90增加,其均值rm无明显变化.

The recrystallization texture evolution and mechanical properties of cold-rolled BH （bake-hardening）-IF （interstitial free ） steel were investigated under different annealing parameters. The results indicated that the tensile strength and the elongation increase with increasing heating rate. In the fully recrystallized condition, the ultra-rapid heating gives rise to substantially refined structures with an unconspicuous reduction of average ferrite grain size. Under the condition of ultra-rapid heating rate, XRD texture analysis showed that the difference in 7 texture components and orientation intensity of BH-IF steel get narrow and the T texture becomes more homogenous. The strong -y texture is obtained simultaneously for both rapid and normal heating rate. The intensity of { 1 1 1 } texture increases with increasing holding time, so the r value increases. Under the ultra-rapid heating rate, the r0 value decreases and the r90 increases, while the rm （average） remains almost unchanged.