曾周燏
,
陈礼清
,
朱伏先
,
刘相华
材料热处理学报
通过热力学软件计算、组织观察以及显微硬度测定,研究固溶温度为850～1200℃时403Nb耐热钢中析出相的溶解与析出行为。结果表明：该耐热钢在高温下主要存在M23C6和MX两种类型碳化物;其中,M23C6型碳化物在900℃左右就完全溶解,而MX型碳化物则相对较稳定,在固溶温度超过1000℃时才开始缓慢溶解。随着固溶温度的升高,MX型碳化物颗粒逐渐减少且颗粒平均尺寸不断长大,但其中非平衡成分的低Nb含量MX型碳化物不断溶解,而平衡成分的高Nb含量MX型碳化物则不断长大。在固溶温度为1150℃时,403Nb钢中开始析出对性能不利的δ铁素体,且随固溶温度的升高,δ铁素体含量逐渐增多。
关键词:
403Nb
,
固溶热处理
,
碳化物
,
δ铁素体
Zhouyu ZENG
金属学报(英文版)
A static recrystallization behavior between the rolling passes of a martensitic heat-resistant stainless steel 403Nb has been studied by OM, TEM and double-hit thermo-mechanical simulator to explore the effects of deformation temperature, strain rate, strain and the prior austenite grain size. The results show that increases of deformation temperature and strain rate and strain can promote the static recrystallization of 403Nb steel. Static recrystallization also proceeds faster when the prior austenite grain size is smaller. Microstructural observation indicates that the volume fraction of static recrystallization increases with prolonged interval of the rolling passes. Strain-induced precipitation can lead to an appearance of a platform in the kinetic curve of static recrystallization. Different from the conventional micro-alloying steel, the strain-induced precipitates in 403Nb steel during hot rolling are carbides containing Nb and Cr.
关键词:
403Nb
