Characteristics of deep penetration laser welding of dissimilar metal Ni-based cast superalloy K418 and alloy steel 42CrMo

Abstract

Experimental trials of autogenous deep penetration welding between dissimilar cast Ni-based superalloy K418 and alloy steel 42CrMo flat plates with 5.0 mm thickness were conducted using a 3 kW continuous wave (CW) Nd:YAG laser. The influences of laser output power, welding velocity and defocusing distance on the morphology, welding depth and width as well as quality of the welded seam were investigated. Results show that full keyhole welding is not formed on both K418 and 42CrMo side, simultaneously, due to the relatively low output power. Partial fusion is observed on the welded seam near 42CrMo side because of the large disparity of thermal-physical and high-temperature mechanical properties of these two materials. The microhardness of the laser-welded joint was also examined and analyzed. It is suggested that applying negative defocusing in the range of Raylei length can increase the welding depth and improve the coupling efficiency of the laser materials interaction. r

Interface microstructure and mechanical properties of laser welding copper–steel dissimilar joint

“…By comparing with electron-beam welding, the laser welding is not restricted by vacuum condition. Hence, using the laser welding to fabricate the dissimilar joints has been attractive in the recent years [3][4][5]. However, the detailed research on the microstructure and mechanical properties of the laser-welded copper-steel dissimilar joints were relatively few.…”

Optimization of Laser Keyhole Welding Strategies of Dissimilar Metals by FEM Simulation

“…The selection of combination of materials has been performed taking also into account real industrial applications: joining of ferritic or martensitic to austenitic stainless steels and ferritic to martensitic steels are very common in nuclear power generation industry, [4,6,7,[40][41][42] in the chemical, petrochemical, and oil and gas industries, [4,6,7] especially in heat exchangers [43] and hydraulic valves, [20,21] and in the automotive industry [44] ; joining of nickel-based alloys to alloy steels is commonly used in turbocompressor rotors [45] and in power plant and electrical applications. [42] B. FEM Simulation of Laser Keyhole Welding For the simulation of laser keyhole welding, the FEM commercial software SYSWELDÒ has been employed.…”

Application of direct laser melting to restore damaged steel dies

“…This figure shows the deepest penetration possible with current technology, not necessarily the optimum penetration conditions. The discontinuity in the curve near 0 J/mm 2 to 50 J/mm 2 may represent the transition from conduction melting to deep penetration by the keyhole mode [10]. The laser energy density can be estimated by…”

“…The automotive industry, in which wear resistance on certain surfaces is desired, has been one of the most important application areas for laser hardening [2]. Recent reviews of the principles and applications of laser treatments describe the use of lasers as a controlled heat source for transformation hardening [3][4][5][6][7][8][9][10]. These research results assist with evaluations of the feasibility of laser treatments for repair methods.…”