POSITION WELDING OF 960 MPa ULTRA-HIGH-STRENGTH STEEL

摘要

High-strength and ultra-high-strength steels are usedmore and more frequently in the engineering industry.The welding of high-strength steels requires lower heatinput welding processes to achieve matching joints.Laser and laser-GMA hybrid welding processes areused for the welding of these kinds of special steels.The Finnish steel maker Rautaruukki makes highstrengthand ultra-high-strength steels under thetrademark Optim. In earlier studies, the weldingposition for these steels has been a flat position(PA/1G). In this study, the welding position was a flatposition, but a horizontal (PC/2G) and an overheadposition (PE/4G) were also tested. The test materialwas an ultra-high-strength steel Optim 960 QC with athickness of 6 mm. The laser-GMA hybrid weldingtests were performed with a Trumpf 12 kW disk laserequipped with a Fronius TIME 5000 Digital GMApower source. Some comparative tests were performedusing GMA welding and laser welding. The fillermaterials used were Esab OK Autrod 12.50 (ISO14341, G42 G3Si1) and Union X96 (ISO 16834, G89Mn4Ni2CrMo) with a diameter of 1 mm.