H. R. Hou
,
Q. Y. Liu
,
Q. A. Chen and H. Dong Division of Structural Materials
,
Central Iron & Steel Research Institute
,
Beijing 100081
,
China
金属学报(英文版)
Heavy deformation and controlled cooling is one of the most effective effective ways for grain refinement in HSIA steels. In this paper, experimental specimens are prepared with a commercial linepipe steel grade X65, and the chemical compositions are (wt% ): Fe-0.094C-1.42Mn-0. 29Si-0. 045Nb-0. 008Ti. After heavy deformation with 80% reduction in non-recrystallization range of austenite, and at controlled cooling rates from 2K/s to 64K/s, the grain sizes vary from 9.55μm to 1.06μm.It is shown by the results that a linear relationship still remains between the yield strength and reciprocal of square root of ferrite grain size as grain size is refined to 1m.The ultra-fine grains might be dynam- ically formed through the deformation-induced transformation when reduction is large enough.The grain sizes decrease when the cooling rates increase.When the cooling rates increase over 10K/s, the grain sizes are rarely changed. The particles distribute on grain boundaries, sub-grain boundaries, deformed bands and within the ferrite grains.
关键词:
microalloyed steel
,
null
,
null
,
null
沈奎
,
卢立华
,
廖舒纶
,
麻晗
材料热处理学报
对铌钒微合金化高碳钢的奥氏体晶粒尺寸、连续冷却转变动态曲线(CCT图)以及等温转变曲线(TTT图)进行了测定,研究加热温度、冷却速度和保温温度对组织性能的影响.结果表明:实际生产中,应将加热温度控制在1100℃以下,避免奥氏体晶粒的粗化;相变前冷速控制在8 K/s以上,相变温度为620 ～650℃,相变温度区间内冷速控制在1.0～2.5 K/s,可获得均匀的索氏体组织和较好的性能.
关键词:
晶粒度
,
热模拟
,
控制冷却
,
显微组织
