Microstructural Study of 17-4PH Stainless Steel after Plasma-Transferred Arc Welding

Materials

Dewei Deng¹  Rui Chen¹  Qi Sun¹  Xiaona Li¹ 

[1] School of Material Science and Engineering, Dalian University of Technology, Dalian 116024, China; E-Mails:

关键词: heat affected zone;    17-4PH;    Co-based alloy;    microstructure;    base metal;   

DOI  :  10.3390/ma8020424

来源: mdpi

【 摘 要 】

The improvement of the surface qualities and surface hardening of precipitation hardened martensitic stainless steel 17-4PH was achieved by the plasma-transferred arc welding (PTAW) process deposited with Co-based alloy. The microstructure of the heat affected zone (HAZ) and base metal were characterized by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that there are obvious microstructural differences between the base metal and HAZ. For example, base material is transformed from lath martensite to austenite due to the heateffect of the welding process. On the other hand, the precipitate in the matrix (bar-like shape Cr₇C₃ phase with a width of about one hundred nanometres and a length of hundreds of nanometres) grows to a rectangular appearance with a width of about two hundred nanometres and a length of about one micron. Stacking fault could also be observed in the Cr₇C₃ after PTAW. The above means that welding can obviously improve the surface qualities.

【 授权许可】

CC BY   
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