Microstructure refinement and properties of 1.0C-1.5Cr steel in a duplex treatment combining double quenching and laser surface quenching

2020 ◽  
Vol 776 ◽  
pp. 138994
Author(s):  
Zhen-xing Li ◽  
Bing-qian Tong ◽  
Qun-li Zhang ◽  
Jian-hua Yao ◽  
Volodymyr Kovalenko
Keyword(s):  
Laser Surface ◽  
Microstructure Refinement ◽  
Duplex Treatment ◽  
Surface Quenching ◽  
Double Quenching

Effect of process parameters on the microstructure evolution of laser surface quenched Ni-Al bronze

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040029
Author(s):  
Zhenbo Qin ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
Wenbin Hu ◽  
Zhong Wu
Keyword(s):  
Grain Boundary ◽  
Process Parameters ◽  
Microstructure Evolution ◽  
Laser Scanning ◽  
Threshold Value ◽  
Laser Surface ◽  
High Rate ◽  
Fine Grained ◽  
Surface Quenching ◽  
Overlap Ratio

Laser surface quenching technology was used to modify the surface microstructure of as-cast Ni-Al bronze (NAB). The modified microstructure was studied by scanning electron microscopy (SEM), and the effect of laser process parameters on microstructure evolution was investigated. It was found that a fine-grained zone with fully [Formula: see text] phase microstructure formed on the surface of NAB. The depth of the fine-grained zone increased with the increase of laser power, and surface melting occurred when the power reached a threshold value. Laser scanning at a low rate caused the coarsening of grain boundary, while too high rate led to incomplete quenching. Spot overlap ratio determined the microstructure of the superimposed area, and unsuitable ratio would cause bulky [Formula: see text] precipitation at the grain boundary or incomplete transformation from [Formula: see text] phase to [Formula: see text] phase.

Effects of Laser Energy Density On Carbide Dissolution, Element Distribution and Microstructure Evolution of AISI P20 Steel During Laser Surface Quenching

2021 ◽  
Author(s):  
Zhuoyuan Li ◽  
Jian Zhang ◽  
Yang Liu ◽  
Qingmao Zhang ◽  
Xizhang Chen ◽  
...  
Keyword(s):  
Energy Density ◽  
Microstructure Evolution ◽  
Laser Energy ◽  
Element Distribution ◽  
Laser Surface ◽  
Laser Energy Density ◽  
Low Carbon ◽  
Aisi P20 ◽  
Surface Quenching ◽  
Carbide Dissolution

Abstract Laser surface quenching (LSQ) was performed on AISI P20 mould and hot-working die steel with an objective to improve surface characteristics. The steel was treated under three different process parameter conditions. The microstructure, element distribution and residual stresses were investigated through SEM, EDS and XRD analyses. The effect of laser energy density on carbide dissolution/ablation, microstructure evolution were thoroughly investigated. The dissolution/ablation of carbides significantly affected the formation of martensite and retained austenite, and the distribution of elements and phase in the microstructure. The results of the study and analyses of treated surface revealed that the LSQ treatment significantly improved the microstructure, eliminated the pores or other defects. Furthermore, the degree of carbide dissolution/ablation was closely related to the laser energy density. Comparing to Cr7C3, Cr3C2 was more difficult to dissolve at lower laser energy density. Thus, those incompletely dissolved Cr3C2 would hinder the growth of austenite and reduce the carbon content in austenite and lead to the formation of low-carbon martensite. The highest laser energy density (150 J/mm2), was able to produce finer microstructure and significantly reduced the inhomogeneity in distribution of Cr between the poor and the rich Cr areas.

Study on Corrosion Resistance Property of Welding HAZ Treated by Laser Surface Quenching

2012 ◽  
Vol 49 (7) ◽  
pp. 071404
Author(s):  
李艳丽 Li Yanli ◽  
李玲 Li Ling ◽  
刘欣 Liu Xin ◽  
刘洁 Liu Jie
Keyword(s):  
Corrosion Resistance ◽  
Laser Surface ◽  
Resistance Property ◽  
Corrosion Resistance Property ◽  
Surface Quenching

Study on Corrosion Resistance of Welding HAZ Treated by Laser Surface Quenching

2012 ◽  
Vol 512-515 ◽  
pp. 2321-2324
Author(s):  
Yan Li Li ◽  
Fang You Hu ◽  
Jia Rui Qi ◽  
Pei Zhong Zhao ◽  
Xiao Mei Zhang
Keyword(s):  
Corrosion Resistance ◽  
Surface Treatment ◽  
Processing Parameters ◽  
Laser Surface ◽  
New Technique ◽  
Laser Surface Treatment ◽  
Treatment Technology ◽  
Laser Quenching ◽  
Corrosion Resistance Property ◽  
Surface Quenching

Generally, the welding HAZ is more sensitive to corrosion. In order to increase the corrosion resistance of the welding HAZ in aircraft structures, the laser surface treatment technology was used to treat the welding HAZ. In this study, the processing parameters of the laser surface treatment were optimized. According to our study, the laser quenching can increase the corrosion resistance property obviously. The laser surface treatment new technique has been used in the maintenance of the airplane structures, which has better application outlook.

Study on CO2 Laser Surface Hardening of 17-4PH Stainless Steel

2011 ◽  
Vol 239-242 ◽  
pp. 73-76
Author(s):  
Jun Wei Zhang ◽  
Gang Lei ◽  
Shu Chen Pan ◽  
Fa Yu Wu
Keyword(s):  
Stainless Steel ◽  
Phase Transformation ◽  
Aging Treatment ◽  
Secondary Phase ◽  
Hardened Layer ◽  
Laser Surface ◽  
Transformation Zone ◽  
Fine Grain ◽  
The Matrix ◽  
Surface Quenching

At present work, the microstructure and corresponding hardness of 17-4PH stainless steel were investigated by the process of CO2 laser surface quenching and aging treatment. The hardness of the phase transformation zone in the hardened layer was 433.2HV, higher than 378.1HV of the matrix, which was attributed to the fine-grain and solution strengthening after laser quenching. The hardness of the phase transformation zone increased further to 464.5HV after an aging treatment at 520°C due to the precipitation strengthening of fine secondary phase particles.

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