N80钢油管QPQ处理后的力学性能  

Mechanical properties of N80 steel oil tube after QPQ treatment

作　　者：包文强[1] 罗德福[1] 张磊[1] 

机构地区：[1]西华大学先进材料及能源研究中心,四川成都610039

出　　处：《金属热处理》2016年第5期57-61,共5页Heat Treatment of Metals

基　　金：国家自然科学基金(51077730)

摘　　要：采用API标准拉伸试验测试了650℃高温QPQ处理及未处理N80钢油管的力学性能,借助OM、SEM观察和分析了样品基体组织、断口形貌及渗层微裂纹。结果表明:QPQ处理的N80钢油管综合力学性能达到API标准要求;QPQ处理后的N80钢油管基体组织粗化,表面硬化明显。QPQ处理前后屈服强度、抗拉强度变化量均小于5%;与镀铬表面的微裂纹缺陷引起塑性下降类似,QPQ处理样品疏松层上萌生的微裂纹导致伸长率平均下降5%。Mechanical properties of N80 steel oil tube before and after QPQ treatment at 650 ℃ were measured though API standard tensile test. The microstrueture, fracture morphology and microeracks were observed and analyzed by means of optical microscopy and scanning electron microscopy. The results show that the mechanical properties of the N80 steel oil tube after QPQ treatment satisfy the API standard requirement. The mierostructnre coarsing and surface hardening are evident after QPQ treatment. Both the yield strength and tensile strength vary less than 5% compared with that of the untreated sample. Similar to the microcrack defects in the surface of chrome plating causing plastic drop, the initiation of microcracks in loose layer of QPQ treatment leads to the decrease of the elongation on average by 5% compared with the untreated sample.

关 键 词：N80钢油管 QPQ处理 API标准 力学性能 

分 类 号：TG115.52[金属学及工艺—物理冶金]