摘要
采用SEM、EBSD和高温拉伸试验等方法研究了长期时效对一种隔热油管钢显微组织和力学性能的影响。结果表明:无论在350℃还是400℃长期时效,在时效2000 h时,显微组织中的马氏体特征仍很明显,时效5000 h后,马氏体板条特征基本消失。随时效时间的延长,碳化物颗粒尺寸略有增加。抗拉强度Rm、屈服强度Rt0.5,在长期时效2000 h前不仅不降低,反而略有增加,长期时效5000 h后明显降低。N80-Q钢的断后伸长率A,在350℃长期时效时,随时间的延长变化不大,在400℃长期时效时有略微降低的趋势。
Effects of long term aging on microstructure and properties of heat insulation oil pipe steel were investigated by means of SEM,EBSD and tensile test at high temperature. The results show that the features of martensite lath are still obvious after aging at 350 ℃ and400 ℃ for 2000 h. Extending the aging time to 5000 h martensite lath disappears and recrystallization occurs. The size of carbide increases slightly with the increasing of aging time. The tensile strength( Rm) and yield strength( Rt0. 5) of the steel aged at 400 ℃ for1000 h slightly decrease and then slighly increase after aging for 2000 h,and decrease obviously after aging for 5000 h. With the prolongation of aging time at 350 ℃,there is little change of the elongation( A),but an appreciably decreasing trend of the elongation( A)is observed with the increase of aging time at 400 ℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第6期149-153,共5页
Transactions of Materials and Heat Treatment
基金
山东省自然科学基金(ZR2013EMM005)
关键词
隔热油管
长期时效
显微组织
力学性能
heat insulation oil pipe
long term aging
microstructure
property
