热处理工艺对403Nb钢组织与蠕变性能的影响  

Effect of heat treatment process on microstructure and creep properties of 403Nb steel

作　　者：尚丽娟[1] 王晓亮[1] 张特[1] 伦建伟[1] 陈礼清[2] 刘相华[2] 

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110178 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110004

出　　处：《材料热处理学报》2011年第3期85-89,94,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(50634030)

摘　　要：为扩大403Nb耐热钢的使用范围,比较研究了热连轧及热处理态403Nb钢的组织及蠕变性能。结果表明:403Nb钢在高温轧制时发生了动态回复及动态再结晶,组成相包括:α-Fe、Cr23C6及少量的NbC。其中,碳化物颗粒粗大,分布不均。经1050℃淬火后,获得了板条马氏体及残留的NbC。随着淬火温度的提高,晶粒有所长大,当温度达到1150℃时,出现较多沿晶界分布的δ铁素体。采用优化的热处理工艺,即1100℃淬火、650℃回火时,在原马氏体板条内及板条间弥散析出大量纳米级以Cr23C6为主的碳化物,此时,钢的使用温度及蠕变寿命可大幅度提高。文中阐述了钢组织的形成机制。Microstructure and creep properties of 403Nb steel processed by continous hot slab rolling and different heat treatment were investigated.Results show that dynamic recovery and dynamic recrystallization are taken place during high temperature rolling in 403Nb steel.Microstructure of the steel consists of α-Fe,（Fe,Cr）23 C6 and（Fe,Cr,Nb） C phases,and carbide particles are coarse relatively and its distribution is inhomogeneous.Microstructure of 403Nb steel is lath martensite and residual（Nb,Fe,Cr）C by quenching at 1050 ℃.The grain size of 403Nb steel increases slightly with the increase of quenching temperature.Delta ferrite appears largely along grain boundary for 403Nb steel quenched at 1150 ℃.Dispersed nano-sized Cr23 C6 carbides precipitate in prior martensite lath and between martensite laths in the hot rooled 403Nb steel after quenching from 1100 ℃ and tempering at 650 ℃,and creep property and service temperature of the steel are improved apparently.The formation mechanism of microstructure in the heat-treated steel is also discussed.

关 键 词：403Nb钢 淬火 回火 组织 蠕变 

分 类 号：TG142.73[一般工业技术—材料科学与工程]