退火对Fe-Cr-Al-Mn双相不锈钢组织及性能的影响

设计制备了一种新型的Fe-Cr-Al-Mn资源节约型双相不锈钢,对其进行高温单相铁素体热轧,研究冷轧后不同退火工艺对其显微组织、力学性能和耐腐蚀性的影响。结果表明,Fe-Cr-Al-Mn钢冷轧后,粗大α相晶粒破碎细化,退火后奥氏体在铁素体晶界形核长大,随退火时间的增加,奥氏体体积分数逐渐增加。随退火温度升高,奥氏体含量减少,伸长率和耐点蚀性能均表现出先增强再减弱的趋势。经800 ℃×4 h退火后,表现出均匀的铁素体和奥氏体相比例和晶粒尺寸,试验钢的强度、伸长率和抗点蚀性能综合性能良好。

Effect of annealing on microstructure and properties of a Fe-Cr-Al-Mn duplex stainless steel

A new type of resource-saving duplex stainless steel Fe-Cr-Al-Mn was designed, prepared, and hot rolled in the high temperature single-phase ferrite (α) region. The effects of different annealing processes on the microstructure, mechanical properties and corrosion resistance after cold-rolling were further studied. The results show that the coarse α-phase grains are broken and refined after the cold rolling. During the annealing process, austenite nucleates and grows at the ferrite grain boundaries. As the annealing time increases, the volume fraction of austenite gradually increases. With the increases of annealing temperature, the volume fraction of austenite decreases, both the elongation and the pitting corrosion resistance show a tendency to increase first and then decrease. After 800 ℃×4 h annealing, the phase ratio and grain size of ferrite and austenite are uniform, which results in excellent combination of strength, elongation and pitting resistance.