形变退火后铁素体不锈钢的晶界组成及腐蚀特性

Constitute and Corrosion Behaviors of Grain Boundary in Cold-rolled and Annealed Ferritic Stainless Steel

采用电子背散射和SEM技术研究了经85%冷轧的铁素体不锈钢在1000℃退火过程中晶粒组织、取向织构和晶界取向差的变化规律以及晶界的腐蚀特性。结果表明,退火初期晶粒长大不显著;当退火时间达到2 h时,晶粒长大,平均晶粒尺寸达到65μm,同时晶粒的{100}<hkl>织构明显增强,由此导致的小角度晶界比例提高。晶界腐蚀实验表明,小角度晶界具有较高的晶界腐蚀抗力。

The microstructure,grain orientation texture and misorientation were investigated using EBSD and SEM technology in cold-rolled and annealed ferritic stainless steel.The results show that,when the cold-rolled specimens with the thickness reduction of 85% are annealed at 1000 ℃ for varying time from 30 min to 2 h,grain size has little change at the early stage.The average grain size increases significantly after 2 h annealing,which reaches 65 μm.In the meanwhile,strong{100}hkl grain texture occurs and resulted in a high frequency of low angle grain boundaries,which posses better intergranular corrosion resistance.