Laser Beam Welding of 600 MPa Quenched and Tempered High-Strength Steel  

作　　者：Pritchard Elmon Marozva Bruno Roberts Mose Abdel-Monem El-Batahgy Thomas Ochuku Mbuya Pritchard Elmon Marozva;Bruno Roberts Mose;Abdel-Monem El-Batahgy;Thomas Ochuku Mbuya(Department of Mechanical Engineering, Pan African University Institute for Basic Sciences, Technology and Innovation, Nairobi, Kenya;Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya;Manufacturing Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Cairo, Egypt;Department of Mechanical & Manufacturing Engineering, University of Nairobi, Nairobi, Kenya)

机构地区：[1]Department of Mechanical Engineering, Pan African University Institute for Basic Sciences, Technology and Innovation, Nairobi, Kenya [2]Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya [3]Manufacturing Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Cairo, Egypt [4]Department of Mechanical & Manufacturing Engineering, University of Nairobi, Nairobi, Kenya

出　　处：《World Journal of Engineering and Technology》2022年第2期241-253,共13页世界工程和技术（英文）

摘　　要：Conventional fusion arc welding of high-strength quenched and tempered steel can be improved through the use of non-conventional laser beam welding. This article presents the investigations of autogenous bead on plate and butt CO₂ Laser Welding (LW) of 7 mm thick high-strength quenched and tempered low alloy SM570 (JIS) steel plates. The influence of laser welding parameters, mainly welding speed, defocusing distance and shielding gas flow rate on the weld profile, i.e., weld zone penetration depth and width, microstructure and mechanical properties of welded joints was determined. All welded joints showed smooth and uniform weld beads free from superficial porosity and undercuts. The selected best welding conditions were a laser power of 5.0 kW, welding speed of 500 mm/min, argon gas shielding flow rate of 30 L/min and a defocusing distance of -0.5 mm. It was observed that these conditions gave complete penetration and minimized the width of the weld bead. The microstructure of the welded joints was evaluated by light optical microscopy. The weld metal (WM) and heat-affected zone (HAZ) near weld metal achieved maximum hardness (355 HV). The tensile fractured samples showed the ductile mode of failure and ultimate tensile strength of 580 MPa.Conventional fusion arc welding of high-strength quenched and tempered steel can be improved through the use of non-conventional laser beam welding. This article presents the investigations of autogenous bead on plate and butt CO₂ Laser Welding (LW) of 7 mm thick high-strength quenched and tempered low alloy SM570 (JIS) steel plates. The influence of laser welding parameters, mainly welding speed, defocusing distance and shielding gas flow rate on the weld profile, i.e., weld zone penetration depth and width, microstructure and mechanical properties of welded joints was determined. All welded joints showed smooth and uniform weld beads free from superficial porosity and undercuts. The selected best welding conditions were a laser power of 5.0 kW, welding speed of 500 mm/min, argon gas shielding flow rate of 30 L/min and a defocusing distance of -0.5 mm. It was observed that these conditions gave complete penetration and minimized the width of the weld bead. The microstructure of the welded joints was evaluated by light optical microscopy. The weld metal (WM) and heat-affected zone (HAZ) near weld metal achieved maximum hardness (355 HV). The tensile fractured samples showed the ductile mode of failure and ultimate tensile strength of 580 MPa.

关 键 词：Laser Welding High-Strength Steel Quenched and Tempered Bead on Plate Joint Butt Joint Heat-Affected Zone (HAZ) CO2 Autogenous Laser Welding Mechanical Properties 

分 类 号：TG1[金属学及工艺—金属学]