热老化对铸造双相不锈钢显微组织的影响

Effect of Thermal Aging on Microstructures of Cast Duplex Stainless Steel

用光学金相(OM)和透射电镜(TEM)等分析方法,研究了法国产Z3CN20-09Mα+γ铸造双相不锈钢(CSS)在400℃加速老化试验后显微组织的变化,探讨热老化对显微组织的影响。结果表明,Z3CN20-09Mα+γ铸造双相不锈钢组织为奥氏体基体上分布着不连续的岛状铁素体,主要形态为条带状和花边状。随老化时间的延长,在局部区域铁素体的形态由不连续的岛状和花边状变为尖锐的长条。奥氏体内的位错、层错也有明显的减少,在晶界处有析出物、位错上有沉淀物的出现。

The microstructural evolution of Z3CN20-09Mα＋γ duplex stainless steel after accelerated aging at 400 ℃ was studied by optical microscope and transmission electronic microscope. The results show that the microstructure of Z3CN20-09M CSS is stripped and laced ferrites which are discontinuously distributed in the austenite matriix. With increasing the thermal aging time, the morphology of some ferrites changes from discontinuous island and laced shape to sharp in some areas. The density of dislocations and faults decrease obviously and there were precipitated phase on the grain boundary and the dislocations.