摘要
高锰TWIP钢的塑性机制与其堆垛层错能有关。采用试验法和热力学计算法确定TWIP钢层错能的研究结果存在差异,TWIP效应与层错能的对应关系也未达成一致。高锰TWIP钢凝固温区宽,凝固时容易形成疏松、偏析等铸态缺陷。铸态TWIP钢高温时的断面收缩率均低于40%,可能导致连铸弯矫时开裂。水平连铸和双辊薄带连铸在TWIP钢生产上具有突出优势。TWIP钢的热轧温度区间窄,与其固相线温度低和高温塑性差有关。冷轧后连续退火温度和退火时间也尚在摸索之中。Fe-Mn-Si-Al系TWIP钢的强化机制以孪晶形成动态细化晶粒为主,而Fe-Mn-C-(-Al)系TWIP钢中动态应变时效可能是主导作用。TWIP钢的延迟断裂敏感性可通过Al合金化来改善,其主要机制是在试样表层下形成的α-Al2O3层阻止氢的渗入。
The plastic mechanism of high manganese TWIP steel is closely related to its stacking fault energy（SFE）.Results on determination of TWIP steel stacking fault energy from experiment and thermodynamic calculation are different,and the SFE range in which TWIP effect occurs is also not consistent among various studies.It is liable to observe the porosity and segregation defects in as cast TWIP steel because of the large margin between liquidus and solidus.The reduction of area for as cast TWIP steel is below 40%,which possibly leads to dendrites cracks during bending and straightening process in conventional continuous casting.Horizontal continuous casting and twin roll strip casting show distinctive advantages in TWIP steel casting.The temperature range for TWIP steel hot rolling is very narrow which is resulted from the low solidus and weak hot ductility.Annealing temperature and time after cold rolling are still in laboratory research stage.The strengthening mechanism for Fe-Mn-Si-Al TWIP steel is mainly due to the dynamic Hall-Petch effect by deformation twins,while for Fe-Mn-C（-Al）TWIP steel,dynamic strain aging should be the primary factor.Al alloying in TWIP steel is helpful to improve the delayed fracture resistance of TWIP steel,attributed to theα-Al2O3 layer under specimen surface which can prevent hydrogen diffusion.
出处
《中国冶金》
CAS
2014年第7期6-16,共11页
China Metallurgy
基金
北京科技大学钢铁冶金新技术国家重点实验室的资助课题(41603013)
冶金新技术国家重点实验室的资金支持
关键词
TWIP钢
层错能
强化机制
延迟断裂
TWIP steel
stacking fault energy
strengthening mechanism
delayed fracture
