Effects of laser heat treatment on salt spray corrosion of1Cr5Mo heat resistant steel welding joints
来源期刊：中南大学学报(英文版)2015年第10期
论文作者：KONG De-jun GUO Wei
文章页码：3722 - 3730
Key words：laser heat treatment; 1Cr5mo heat-resistant steel; welding joint; salt spray corrosion
Abstract: The surface of 1Cr5Mo heat-resistant steel welding joint was processed with CO2 laser, and the corrosion behaviors before and after laser heat treatment (LHT) were investigated in the salt spray corrosion environments. The microstructures, phases, residual stresses and retained austenite content of 1Cr5Mo steel welding joint before and after LHT were analyzed with optical microscope and X-ray diffraction, respectively. The cracking morphologies and chemical compositions of corrosion products after salt spray corrosion were analyzed with field emission scanning electron microscopy (FESEM) and energy disperse spectroscopy (EDS), respectively, the polarization curves were measured on a PS-268A type electrochemical workstation, and the mechanism of corrosion resistance by LHT was investigated as well. The results show that the passive film of original sample is destroyed owing to the corrosive media penetrating into the subsurface, resulting in the redox reaction. The content of residual austenite in the surface and the self-corrosion potential are increased by LHT, which is contributed to improving the capability of salt spray corrosion resistance.
KONG De-jun(孔德军)1, 2, GUO Wei(郭卫)1
(1. College of Mechanical Engineering, Changzhou University, Changzhou 213164, China;
2. Jiangsu Key Laboratory of Materials Surface Science and Technology
(Changzhou University), Changzhou 213164, China)
Abstract:The surface of 1Cr5Mo heat-resistant steel welding joint was processed with CO2 laser, and the corrosion behaviors before and after laser heat treatment (LHT) were investigated in the salt spray corrosion environments. The microstructures, phases, residual stresses and retained austenite content of 1Cr5Mo steel welding joint before and after LHT were analyzed with optical microscope and X-ray diffraction, respectively. The cracking morphologies and chemical compositions of corrosion products after salt spray corrosion were analyzed with field emission scanning electron microscopy (FESEM) and energy disperse spectroscopy (EDS), respectively, the polarization curves were measured on a PS-268A type electrochemical workstation, and the mechanism of corrosion resistance by LHT was investigated as well. The results show that the passive film of original sample is destroyed owing to the corrosive media penetrating into the subsurface, resulting in the redox reaction. The content of residual austenite in the surface and the self-corrosion potential are increased by LHT, which is contributed to improving the capability of salt spray corrosion resistance.
Key words:laser heat treatment; 1Cr5mo heat-resistant steel; welding joint; salt spray corrosion
