With the use of laser welding,it is possible to join different steel,with different thicknesses,with or without the action of protective layers.The quality of laser radiation makes it possible to get certain character...With the use of laser welding,it is possible to join different steel,with different thicknesses,with or without the action of protective layers.The quality of laser radiation makes it possible to get certain characteristics that are impossible to get by other processes,such as high welding speeds,less metallurgical effects suffered by the heat-affected zone(ZAC),and this process also does not require filler metal,therefore it is free from possible contamination.Combined with traditional welding methods,laser welding produces narrower weld beads,allowing for better prevention of corrosion and thermal distortions.Although the process already has high industrial knowledge,some random defects,such as porosities and inconsistencies,are still found.This work presents a systematic study to determine the influence of laser welding parameters and how these parameters influence welding defects.For this,the experimental part was carried out in the welding laboratory-LABSOLDA,of the Federal University of Santa Catarina-UFSC,during the laser welding processes,a welding speed of 2.4 m/min was reached.For this experiment,argon was used as a shielding gas and 1020 steel was used as the base material.展开更多
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...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 CO<sub>2</sub> 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.展开更多
文摘With the use of laser welding,it is possible to join different steel,with different thicknesses,with or without the action of protective layers.The quality of laser radiation makes it possible to get certain characteristics that are impossible to get by other processes,such as high welding speeds,less metallurgical effects suffered by the heat-affected zone(ZAC),and this process also does not require filler metal,therefore it is free from possible contamination.Combined with traditional welding methods,laser welding produces narrower weld beads,allowing for better prevention of corrosion and thermal distortions.Although the process already has high industrial knowledge,some random defects,such as porosities and inconsistencies,are still found.This work presents a systematic study to determine the influence of laser welding parameters and how these parameters influence welding defects.For this,the experimental part was carried out in the welding laboratory-LABSOLDA,of the Federal University of Santa Catarina-UFSC,during the laser welding processes,a welding speed of 2.4 m/min was reached.For this experiment,argon was used as a shielding gas and 1020 steel was used as the base material.
文摘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 CO<sub>2</sub> 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.
