退火温度对超纯Cr17铁素体不锈钢冷轧板成形性能的影响

Effect of Annealing Temperature on Formability of Cold-Rolled Ultra-purified Cr17 Ferritic Stainless Steel Sheet

对一种铌、钛双稳定化的超纯Cr17铁素体不锈钢的冷轧板进行不同温度的退火实验,探讨了对组织、织构及成形性能的影响.研究结果表明,退火温度是影响成形性能的关键因素.随着退火温度的升高,晶粒的平均尺寸逐渐增大,不均匀化程度逐渐加重.并且,γ纤维织构逐渐增强,α纤维织构逐渐减弱,使-r值逐渐增大,而Δr值变化不大.为了防止"橘皮"缺陷的产生,退火温度应低于1 000℃,平均晶粒尺寸应控制在40μm以下.在保证不产生"橘皮"缺陷的前提下,试验钢的冷轧板经975℃退火后具有最佳的成形性能:-r值高达1.92,Δr值仅为0.12.

The cold-rolled sheet of an ultra-purified Cr17 ferritic stainless steel stabilized with both Nb and Ti was annealed at different temperatures,and the effect of annealing temperature on the microstructure,texture and formability of the sheet was investigated.The results showed that the annealing temperature to the sheet is the key influencing factor on its formability.The average grain size increases gradually and the heterogeneity among all grain sizes is aggravated with increasing the annealing temperature.Moreover,the γ-fiber texture is gradually strengthened while the α-fiber texture is weakened,thus increasing the r-（average strain ratio） gradually with the Δr（planar anisotropy） value changing slightly.To avoid the occurrence of ＂orange peel＂（rough surface）,the annealing temperature should be below 1 000 ℃ and the average grain size should be controlled smaller than 40 μm.In such a way,the finished sheet has the best formability with r-value 1.92 and Δr value 0.12 after annealing at 975 ℃ without ＂orange peel＂.