摘要
针对制备高强韧Fe-1.55C-1.14Cr-1.15Al超高碳钢过程中等温退火工艺的不足,提出先以普通正火来代替等温退火,然后再进行球化的热处理工艺,研究了正火、球化温度对试验钢显微组织的影响,并确定了较佳的正火及球化工艺。结果表明：随着正火温度的升高,试验钢组织中的片状珠光体片层间距增大,网状碳化物减少,采用1 050℃×20min的正火工艺可替代等温退火来细化组织;试验钢的共析转变开始温度为790℃,在该温度及以上出现了大量的球状碳化物,且随温度升高球化越完全,在750～810℃球化会出现三相组织（F-A-Fe3C）;适宜的球化工艺为850℃保温1h,新工艺处理后的奥氏体转变完全,球状碳化物弥散分布在奥氏体基体中。
In view of the shortage of the isothermal annealing process during the preparation of Fe 1.55C1.14Cr-1.15Al ultra-high carbon steel with high strength and toughness, the treatment process composed of first with normalizing instead of isothermal annealing and then spheroidizing was presented. The effects of normalizing temperatures and spheroidizing temperatures on the microstructures of tested steels were studied, and then a relatively optimum normalizing and s pheroidizing process was determined. The results show that with the increase of normalizing temperature, the lamellar spacing of pearlite in the mierostructure of the tested steel increased and the amounts of net-like carbide decreased. The fined microstructure can he obtained after the substitution treatment of normalizing at 1 050 ℃ for 20 min for isothermal annealing. The euteetoid transformation temperature of the tested steel was 790 ℃. At or beyond the temperature, a lot of spheroidized carbides were observed and the spheroidizing completed better and better with the increase of the temperature. The triphase microstructure （F-A-Fe3C） appeared at the temperature between 750 ℃ and 810 ℃ during the spheroidizing process. The appropriate spheroidization process was heating at 850 ℃ for 1 h. The austenite transformed completely and the spheroidized carbides distributed dispersively in austenite substrate after treated with the new process.
出处
《机械工程材料》
CAS
CSCD
北大核心
2016年第2期56-60,共5页
Materials For Mechanical Engineering
基金
浙江省教育厅科研计划资助项目(Y201223080)
江苏高校优势学科二期建设项目(苏政办发[2014]37号)
关键词
超高碳钢
等温退火
正火
球化
ultra-high carbon steel
isothermal annealing
normalizing
spheroidizing
