摘要
以微Nb处理控轧控冷工艺生产的400MPa级超级钢为研究对象,采用'系列冲击实验法'测定系列冲击功,绘制出脆性转变温度曲线·按综合能量法及断口形貌,确定出脆性转变温度为-80℃,并与相同化学成分、普通方法生产的钢板的脆性转变温度加以比较,对这一温度降低的原因进行了分析·分析结果认为,脆性转变温度降低、低温韧性的改善是化学成分、微观组织、轧制工艺综合作用的结果·钢中S、P、Si含量低有利于脆性转变温度的降低、微量Nb的存在有利于脆性转变温度的降低;晶粒细化,亚晶强化是试验钢脆性转变温度降低的组织原因;控轧控冷工艺的采用是降低脆性转变温度的工艺因素·
Series impact tests were carried out to measure the series impact work done to a 400?MPaclass supersteel which was supplied through controlled rolling and cooling rate accelerated with trace element Nb contained, thus giving a brittle transition temperature curve. The brittle transition temperature or ductilebrittle transition temperature(DBTT)of the steel was determined as -80?℃ according to the integrated energy consumption and fracture morphology of the tested samples. Compared with that of other steel sheets of the same composition but rolled in different ways, the reasons of such a lower temperature were analyzed. A conclusion was thus drawn that the decreased DBTT and the improvement of lowtemperature ductility can be attributed to the combination of composition and rolling technique with microstructure and other factors. Low contents of S, P and Si in tested samples are beneficial to the decreasing of DBTT as well as the microalloying element Nb. In addition, refined grain and subgrain strengthening play an important role in decreasing DBTT, and TMCP technique can refine ferrite grain so as to benefit DBTT decreasing.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2003年第11期1057-1060,共4页
Journal of Northeastern University(Natural Science)
基金
国家高技术研究发展计划项目(2001AA332020).
关键词
超级钢
控轧控冷
系列冲击实验
脆性转变温度
低温韧性
supersteel
controlled rolling and cooling
series impact test
brittle transition temperature
low-temperature ductility
