Multi-layer narrow-gap welding of thick S32101 duplex stainless steel was conducted using laser welding with beam wobble process.The phase transition,grain size,phase proportion and crystal texture of welded joint wer...Multi-layer narrow-gap welding of thick S32101 duplex stainless steel was conducted using laser welding with beam wobble process.The phase transition,grain size,phase proportion and crystal texture of welded joint were also studied and compared with gas metal arc welding process.The microhardness and tensile strength were measured and fracture surface was analyzed to evaluate the mechanical properties of welded joints.The results showed that beam wobble technology improved the misalignment of laser beam and filler wire in narrow groove and helped to avoid incomplete fusion defects.Compared to arc welding process,the groove size and heat input were reduced,while welding efficiency was increased.The faster cooling rate and lower temperature gradient of laser wobble welding favored grain refinement,while the austenite content in weld zone decreased.Both the beam wobble and swing arc were conducive to stir weld pool,optimizing the weld microstructure and joint formation.The microstructural variance in various weld passes was caused by the heat input and heat dissipation ability.The microhardness of laser welded joint was lower,while the tensile strength and elongation percentage were higher.The fracture surface of arc welded joint was featured with shallower dimples and cleavage steps.展开更多
In this work, a tandem narrow gap gas metal arc welding（ GMA W） system was developed to improve the efficiency in welding of thicker materials, which are mostly used in shipbuilding and nuclear power plant. A specia...In this work, a tandem narrow gap gas metal arc welding（ GMA W） system was developed to improve the efficiency in welding of thicker materials, which are mostly used in shipbuilding and nuclear power plant. A special welding torch was desgined, where the two wires are fed through the bent contact tip to point to each side of narrow gap groove. Effect of wire distance and bent angle of contact tip on weld bead shape is studied. The experimental results show that defect free weld bead can be obtained when the wire distarwe is 5 mm and bent angle of contact tip is 10% Finally, tandem narrow gap GMAW of 65 mm thick low carbon steel was successfully carried out with one pass per layer. The obtained weld cross-section photo indicates that there is no defect of lack of side fusion or slag inclusion.展开更多
基金supported by the Science and Technology Innovation Program of Hunan Province(2022RC1060 and 2022GK4046)。
文摘Multi-layer narrow-gap welding of thick S32101 duplex stainless steel was conducted using laser welding with beam wobble process.The phase transition,grain size,phase proportion and crystal texture of welded joint were also studied and compared with gas metal arc welding process.The microhardness and tensile strength were measured and fracture surface was analyzed to evaluate the mechanical properties of welded joints.The results showed that beam wobble technology improved the misalignment of laser beam and filler wire in narrow groove and helped to avoid incomplete fusion defects.Compared to arc welding process,the groove size and heat input were reduced,while welding efficiency was increased.The faster cooling rate and lower temperature gradient of laser wobble welding favored grain refinement,while the austenite content in weld zone decreased.Both the beam wobble and swing arc were conducive to stir weld pool,optimizing the weld microstructure and joint formation.The microstructural variance in various weld passes was caused by the heat input and heat dissipation ability.The microhardness of laser welded joint was lower,while the tensile strength and elongation percentage were higher.The fracture surface of arc welded joint was featured with shallower dimples and cleavage steps.
文摘In this work, a tandem narrow gap gas metal arc welding（ GMA W） system was developed to improve the efficiency in welding of thicker materials, which are mostly used in shipbuilding and nuclear power plant. A special welding torch was desgined, where the two wires are fed through the bent contact tip to point to each side of narrow gap groove. Effect of wire distance and bent angle of contact tip on weld bead shape is studied. The experimental results show that defect free weld bead can be obtained when the wire distarwe is 5 mm and bent angle of contact tip is 10% Finally, tandem narrow gap GMAW of 65 mm thick low carbon steel was successfully carried out with one pass per layer. The obtained weld cross-section photo indicates that there is no defect of lack of side fusion or slag inclusion.
