In order to study the effect of Al-Si coating on the microstructure, microhardness and tensile properties of 22MnB5 laser welded joint, the IPG YLR-6000 fiber laser is used to fabricate 1.5 mm thick Al-Si coating 22MnB5 steel laser welding experiment. The results show that the fusion zone and fusion line of the Al-Si coating sample are lath martensite (LM) +Al-rich δ ferrite. However, the microstructure of the fusion zone and fusion line are LM which the Al-Si coating which is removed. The main reason is that the Al-Si coating melts and enters the welding pool during the laser welding process, and the stability of the high temperature δ ferrite increases due to the enrichment of the Al in the part of the fusion zone and the fusion line. At the same time under a rapid cooling conditions, some δ-ferrite can't occur peritectic transformation and it is retained to room temperature. The microhardness distribution of the two welded joints is consistent, and the microhardness of the welded joint is higher than that of the base metal. However, due to the presence of soft phase δ ferrite in the Al-Si coating, the hardness of the fusion zone is lower than that without Al-Si coating. Although the Al-Si coating has an effect on the microstructure and microhardness, it has no effect on the tensile properties. The tensile specimen of the two welded joints are both broken in the base metal, and it is a typical ductile fracture.
CHEN Xiaming
,
WANG Xiaonan
,
SUN Qian
,
ZHANG Min
,
CHEN Changjun
,
DI Hongshuang
. Effect of Al-Si Coating on Microstructure and Properties of 22MnB5 Steel Laser Welded Joint[J]. Journal of Mechanical Engineering, 2018
, 54(6)
: 162
-167
.
DOI: 10.3901/JME.2018.06.162
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