Banded microstructure formation and its effect on the performance of 06Ni9 steel
Focusing on the banded microstructure formed during the production of 06Ni9 steels for cryo-LNG, this paper examines its formation, distribution of alloying elements, structure, hardness, and low-temperature property. The results show that the banded microstructure formed after hot-rolling and cooling of the steel binct in which the element segregation occurred during solidification. The phase change during heat treatment also can cause the formation of the of the banded microstructure of 06Ni9 steel. The white bands are mainly composed of ferrite and reversed austenite, and the black bands are mainly composed of reversed austenite and a certain amount of ferrite. Element segregation and formation of more carbide caused some black regions to appear. Grain refinement of 06Ni9steel is beneficial to the formation of reversed austenite, the redistribution of alloying elements, improving the stability of austenite and the low-temperature toughness of steel. This steel easily undergoes nickel segregation; thus, undergoing a secondary quenching and tempering process is recommended. The refinement of martensite quenching above Ac3,the martensite that is rich in nickel and carbon,residual austenite and a few little of ferrite after secondary quenching lower than Ac3 are beneficial to the formation of high stability austenite. Thus, this can meet the strength and toughness requirement of the low temperature 06Ni9 steel.
06Ni9 steel banded microstructure reversed austenite
Liu Dong-feng Wang Zheng-guo Wei Ying-hui Cui Tian-xie Pan Qi-fa Hou Li-feng
School of Material Science and Engineering , Taiyuan University of Technology, Taiyuan 030024, Shanx School of Material Science and Engineering , Taiyuan University of Technology, Taiyuan 030024, Shanx Technical Center, Taiyuan Iron and Steel Group Co ltd, Taiyuan 030024, Shanxi, China
国际会议
The 6th International Conference on High Strength Low Alloy Steels(第六届高强度低合金钢国际会议HSLA Steels2011)
北京
英文
756-761
2011-05-31（万方平台首次上网日期，不代表论文的发表时间）