轧后冷却和热处理工艺对Nb微合金化V140油井管用钢组织和性能的影响  

Effect of post-rolling cooling and heat treatment processes on microstructure and mechanical properties of Nb-microalloyed V140 steel for OCTG

作　　者：范仲涛 高秀华[1] 袁国[1] 康健[1] Fan Zhongtao;Gao Xiuhua;Yuan Guo;Kang Jian(State Key Laboratory-of Rolling and Automation,Northeastern University,Shenyang Liaoning 110819,China)

机构地区：[1]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110819

出　　处：《金属热处理》2020年第12期1-6,共6页Heat Treatment of Metals

基　　金：中信-CBMM铌钢推广项目。

摘　　要：通过热轧及轧后热处理试验研究了不同工艺对油井管用V140试验钢的力学性能和显微组织的影响,并探讨了Nb对试验钢组织及力学性能的作用。结果表明,高温下析出的Nb(C,N)可以抑制奥氏体的再结晶行为,使精轧过程可在未再结晶区进行,起到细化晶粒的作用,从而提高试验钢的强度与韧性。轧后空冷-离线调质、轧后快冷-回火和轧后快冷-离线调质3种工艺下试验钢的组织均为回火索氏体,组织均匀,力学性能优良,且轧后快冷-回火工艺可以满足V140钢的性能要求,还可以缩短生产流程、节约成本。此工艺的最佳回火温度为660℃,回火时间为30 min。Effects of different processes and the function of Nb on the mechanical properties and microstructure of V140 steel for OCTG(oil country tubular goods)were studied through hot rolling and post-rolling heat treatment experiments.The results show that Nb(C,N)precipitated at high temperature can inhibit the recrystallization of austenite,make the finishing rolling process possible in the nonrecrystallization zone and refine grains,thus improving the strength and toughness of the steel.Under three kinds of processes including postrolling air cooling+offline quenching and tempering,post-rolling fast cooling+tempering,and post-rolling fast cooling+offline quenching and tempering,the microstructures of the steel are all uniform ones of tempered sorbite with excellent mechanical properties.Moreover,the post-rolling fast cooling+tempering process can meet the requirements of mechanical properties,shorten the production process and save cost,with the best tempering temperature and time being 660℃ and 30 min,respectively.

关 键 词：油井管用V140钢 铌 热处理 组织 性能 

分 类 号：TG161[金属学及工艺—热处理]