摘要
采用混合预合金粉末和球磨粉末的方法,制备一种具有双组态结构的铁素体合金钢,其名义成分为Fe-14Cr-3W-0.42Ti-0.32Y。其微观组织与成分相同但是采用全球磨粉末成形的铁素体钢有明显的区别。通过热锻、空冷之后,该合金具有铁素体晶粒和马氏体晶粒混合构成的双组态结构。通过微观组织研究发现了在该合金中发生了局部的αbcc→γfcc→α'bcc相变。同时,这种双组态结构能够较好地均衡合金的强度和韧性。
Ferritic steel with a nominal composition of Fe-14Cr-3W-0.42Ti-0.32Y was prepared by mixing gas-atomized prealloyed powder and mechanically alloyed powder. The microstructure is much different fxom other ferritic steels with the same composition and prepared via only mechanically alloyed powder. A bi-modal structure, which consists of pure ferritic grains and martensitic grains, was obtained after hot forging and air cooling. A phase transformation of αbcc→γfcc→α＇bcc was also discovered in microstructural observation. The bi-modal microstructure shows a good combination of high strength and high ductility.
基金
Projects (50634060,50721003) supported by the National Natural Science Foundation of China
Project (2009AA03Z526) supported by the High-tech Research and Development Program of China
Project supported by the Open-End Fund for Valuable and Precision Instruments of Central South University
关键词
铁素体钢
粉末冶金
相变
双组态结构
力学性能
ferritic steel
powder metallurgy
phase transformation
bi-modal microstructure
mechanical property
