Welding Stainless Steels and Refractory Metals Using Diode-Pumped Continuous Wave Nd:YAG Lasers

Palmer, T A ; Elmer, J W ; Pong, R ; Gauthier, M D

Lawrence Livermore National Laboratory

关键词: Laser Welding;    Welding;    Lawrence Livermore National Laboratory;    Vanadium;    Refractory Metals;   

DOI  :  10.2172/15014822
RP-ID  :  UCRL-TR-206885
RP-ID  :  W-7405-ENG-48
RP-ID  :  15014822

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report provides an overview of a series of developmental welding studies performed on a 2.2 kW Rofin Sinar DY-022 Diode Pumped Continuous Wave (CW) Nd:YAG welder at Lawrence Livermore National Laboratory (LLNL). Several materials systems, ranging from refractory metals, such as commercially pure tantalum and vanadium, to austenitic stainless steels, including both 304L and 21-6-9 grades, are examined. Power input and travel speed are systematically varied during the welding of each materials system, and the width, depth, and cross sectional area of the resulting weld fusion zones are measured. These individual studies are undertaken in order to characterize the response of the welder to changes in these welding parameters for a range of materials and to determine the maximum depth of penetration of which this welder is capable in each materials system. The maximum weld depths, which are on the order of 5.4 mm, are observed in the 21-6-9 austenitic stainless steel at the maximum laser power setting (2200 W) and a slow travel speed (6.4 mm/sec). The next highest weld depth is observed in the 304L stainless steel, followed by that observed in the vanadium and, finally, in the tantalum. Porosity, which is attributed to the collapse of the keyhole during welding, is also observed in the welds produced in tantalum, vanadium, and 304L stainless steel. Only the 21-6-9 austenitic stainless steel welds displayed little or no porosity over the range of welding parameters. Comparisons with similar laser welding systems are also made for several of these same materials systems. When compared with the welds produced by these other systems, the LLNL system typically produces welds of an equivalent or slightly higher depth.