|
|
|
| Phase Transformation and Its Effect on Mechanical Properties of C300 Weld Metal after Aging Treatment at Different Temperatures |
| Shuai YANG1,2,Yun PENG2,Xiao-mu ZHANG2,Zhi-ling TIAN2 |
1. China Railway Materials Technologies Company Limited, Beijing 100036, China
2. State Key Laboratory of Advanced Steel Processes and Products, Central Iron and Steel Research Institute, Beijing 100081, China |
|
|
|
|
Abstract The influence of aging temperature on phase transformation and mechanical properties of weld metal of maraging steel (grade C300) was studied. Microstructure was analyzed by means of optical microscopy, transmission electron microscopy, scanning electron microscopy and energy dispersive spectrum analysis. Gibbs free energy of Ni3Ti and Fe2Mo at different temperature was calculated by Thermal-calc software. The microstructure of weld metal in as-welded state is martensite. The yield strength of weld metal after 430 �� aging process may increase to 1561 MPa from 890 MPa in as-welded state, which is ascribed to the formation of spinodal constitute and GP zones. After 480 �� aging process, there are great deal of Ni3Ti precipitates in the martensite matrix and 10% reverted austenite phase in the cellular grain boundary, and the yield strength increases to 1801 MPa. After aging process at 580 ��, there are many Fe2Mo precipitates in the martensite matrix and 30% reverted austenite phase in the cellular grain boundary, and the yield strength is 1329 MPa, which is the lowest among the three cases. The phase transformation may also influence the toughness. It is found that precipitates make the toughness decrease and reverted austenite increases it. The mechanism of phase transformation on strength and toughness is discussed.
|
|
Received: 15 July 2014
Published: 05 June 2015
|
| Fund:National Key Basic Research and Development Program |
|
Corresponding Authors:
Peng Yun Peng
E-mail: yunpeng21@139.com
|
|
|
|
| [1] |
Zhi-gang Song,En-xiang Pu,. Precipitated phases of superaustenitic stainless steel 654SMO[J]. Chinese Journal of Iron and Steel, 2017, 24(7): 743-749. |
| [2] |
Zhi-gang Song*,Han Feng,Shao��mei Hu. Development of Chinese duplex stainless steel in recent years[J]. Chinese Journal of Iron and Steel, 2017, 24(2): 121-130. |
| [3] |
Si-qian Bao,,*,Yang Xu,Gang Zhao,,Xiang-bin Huang,Huan Xiao,Chuan-long Ye, Na-na Song,Qing-ming Chang. Microstructure, texture and precipitates of grain-oriented silicon steel produced by thin slab casting and rolling process[J]. Chinese Journal of Iron and Steel, 2017, 24(1): 91-96. |
| [4] |
Yi LI,,Yuan��fei LI,Ben XU,Qiu��lin LI,Guo��gang SHU,Wei LIU,. Magnetic Properties of Thermally Aged Fe��Cu Alloys with Pre��deformation[J]. Chinese Journal of Iron and Steel, 2016, 23(9): 981-987. |
| [5] |
Fu-ming LIU,Jian-jun WANG,,Yu-jie LIU,R.D.K. MISRA,Chun-ming LIU,. Effects of Nb and V on Microstructural Evolution, Precipitation Behavior and Tensile Properties in Hot-rolled Mo-bearing Steel[J]. Chinese Journal of Iron and Steel, 2016, 23(6): 559-565. |
| [6] |
Biao JU,Hui-bin WU,Di TANG,Ning DANG. Characterization of (Nb,Ti,Mo)C Precipitates in an Ultrahigh Strength Martensitic Steel[J]. Chinese Journal of Iron and Steel, 2016, 23(5): 495-500. |
|
|
|
|
2015, Vol. 22 
