1. School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, Jiangsu, China 2. School of Materials Science and Engineering, Nanchang Hangkong University,Nanchang 330063, Jiangxi, China 3. Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province, Nanchang 330063, Jiangxi, China
Effect of Aging on Hardening Behavior of 15-5 PH Stainless Steel
1. School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, Jiangsu, China 2. School of Materials Science and Engineering, Nanchang Hangkong University,Nanchang 330063, Jiangxi, China 3. Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province, Nanchang 330063, Jiangxi, China
ժҪ Microstructure transformation and aging hardening behavior of 15-5 PH stainless steel were studied by optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the 15-5 PH stainless steel consists of NbC precipitates and lath matensite with a high dislocation density after solution treatment. With increasing aging temperature and aging time, the martensitic laths were resolved gradually. Meanwhile, the nanometric-sized Cu precipitates gradually coarsened and lost their coherency with the martensite matrix, which exhibited an elliptical shape finally. Fine Cu precipitates can lead to significant dispersion hardening effect, while the coarsened Cu precipitates have no contribution to strengthening. The reversed austenite was observed in the specimens aged at 550 �� and above; moreover, the amount of reversed austenite increased as aging temperature increased. The precipitation hardening behavior of 15-5 PH stainless steel may depend on the balance between the softening caused by the formation of reversed austenite and the hardening caused by the precipitation of copper.
Abstract��Microstructure transformation and aging hardening behavior of 15-5 PH stainless steel were studied by optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the 15-5 PH stainless steel consists of NbC precipitates and lath matensite with a high dislocation density after solution treatment. With increasing aging temperature and aging time, the martensitic laths were resolved gradually. Meanwhile, the nanometric-sized Cu precipitates gradually coarsened and lost their coherency with the martensite matrix, which exhibited an elliptical shape finally. Fine Cu precipitates can lead to significant dispersion hardening effect, while the coarsened Cu precipitates have no contribution to strengthening. The reversed austenite was observed in the specimens aged at 550 �� and above; moreover, the amount of reversed austenite increased as aging temperature increased. The precipitation hardening behavior of 15-5 PH stainless steel may depend on the balance between the softening caused by the formation of reversed austenite and the hardening caused by the precipitation of copper.
��������:National High Technology Research and Development Program of China;National Science and Technology Project of China;Key Laboratory Foundation of Metal Material Microstructure Control of JiangXi Province
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PENG Xin-yuan
E-mail: pxy728@126.com
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Xin-yuan PENG,,,Xian-liang ZHOU,,,Xiao-zhen HUA,,Zhen-wei WEI,Hua-ying LIU. Effect of Aging on Hardening Behavior of 15-5 PH Stainless Steel[J]. �й������ڿ���, 2015, 22(7): 607-614.
Xin-yuan PENG,,,Xian-liang ZHOU,,,Xiao-zhen HUA,,Zhen-wei WEI,Hua-ying LIU. Effect of Aging on Hardening Behavior of 15-5 PH Stainless Steel. Chinese Journal of Iron and Steel, 2015, 22(7): 607-614.
2015, Vol. 22 
