Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1628525 | Journal of Iron and Steel Research, International | 2015 | 8 Pages |
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 °C 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.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Xin-yuan PENG, Xian-liang ZHOU, Xiao-zhen HUA, Zhen-wei WEI, Hua-ying LIU,