Ti微合金化对3.5Ni钢低温韧性的影响  

Effect of Ti miroalloying on the low temperature toughness of 3.5Ni steel

作　　者：李建华[1,2] 吴开明[1] 邱金鳌[1] 

机构地区：[1]武汉科技大学国际钢铁研究院,湖北武汉430081 [2]武汉钢铁(集团)公司研究院,湖北武汉430080

出　　处：《武汉科技大学学报》2012年第3期169-173,共5页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金重点项目(50734004)

摘　　要：利用光学显微镜和透射电镜观察不同Ti含量3.5Ni钢试样的组织及析出物,并通过测定其-80～-120℃的夏比冲击功来研究Ti微合金化对3.5Ni钢低温韧性的影响。结果表明,与0.042Ti试样相比,0.079Ti试样在热轧态和正火+回火态时晶粒大小相同,但其热轧态组织中珠光体细化,且正火+回火态组织中TiN数量增多,平均尺寸约为150nm;正火+回火处理后,0.079Ti试样在-80～-120℃的夏比冲击功为233～23J,均低于0.042Ti试样相应值(234～66J);对于正火+回火态试样,较粗大TiN粒子的析出是造成其低温韧性降低的主要原因。The effect of Ti microalloying on the toughness of the cryogenic pressure vessel 3.5Ni steel was investigated by examining the microstrueture and precipitates of the steel using optical microscopy and transmission electron microscopy and by measuring the charpy impact energy from --80 ℃ to --120 ℃. The results show that the steel containing 0. 079 % Ti has the same average grain size with the steel containing 0. 042% Ti, hut has fewer pearlite in the as-rolled steel and more coarse TiN par- ticles （the average size about 150 nm） in the normalized and tempered steel than the latter. The charpy impact energy of the steel containing 0. 079% Ti has a lower level （233-23 J） than that of the steel containing 0. 042- Ti （234-66 J）. In the normalized and tempered steel, a large number of coarse TiN results in a decrease in the low temperature toughness.

关 键 词：3.5NI钢 TI微合金化 珠光体 TIN 低温韧性 

分 类 号：TG111[金属学及工艺—物理冶金] TG142[金属学及工艺—金属学]