Laser cladding of 420 stainless steel with molybdenum on mild steel A36 by a high power direct diode laser

Abstract

Laser cladding, as one of the most promising surface modification technologies, is being widely applied in industry to improve the wear and corrosion resistance of components. The high energy input and high cooling rate during the cladding process lead to severe metallurgical reactions that determine the microstructure and properties of the cladded layer. In this study, a 3-dimensional (3-D) finite element (FE) model was developed to study heat transfer during laser cladding of 420 stainless steel+ 4% molybdenum on mild steel A36. In this model, the effects of laser-powder interaction, temperature-dependent material properties, latent heat, and Marangoni flow were considered. A method based on mass balance was adopted to predict the clad geometry. The thermal results such as the temperature history, temperature gradient, and solidification rate were investigated. Based on the simulated thermal results, the microstructure and Mo distribution in the clad layer were studied. In order to verify the established model, a series of experiments was conducted by using an 8-kW high-power direct diode laser (HPDDL). Thermocouples and a CCD camera were used to monitor the temperature history and molten pool size. The predicted clad height and width showed a good agreement with the experimental results.

Effects of Low-Temperature Tempering on Microstructure and Properties of the Laser-Cladded AISI 420 Martensitic Stainless Steel Coating

“…By calculating the formulas of Equations (1) and (2), the Cr eq and Ni eq values were 14.6 and 8.87, respectively, as indicated by the red dot in Figure 2a. It is worth mentioning that the 0.55 wt % Ni present in this work, as indicated in Table 1, is higher than those reported in AISI 420 SS with a lean Ni element [2][3][4][5][6][7]. In view of the high hardenability of AISI 420 stainless steel, together with the presence of the austenite stabilizer Ni, it can be reasonably speculated that martensite (M) and austenite (A) coexist in the as-cladded coating in this work.…”

“…Laser cladding, as a simple but efficient surface modification technique, has been extensively utilized in different industrial fields such as surface coating functionalization, component repair and additive manufacturing under harsh service conditions [1,2]. AISI 420 martensitic stainless steel (SS) has been considered as one of the potential alloys for creating additive manufacturing functional coatings/components owing to its high mechanical properties, moderate corrosion resistance and tailored properties by the subsequent heat treatment [2][3][4].…”

“…However, there was only a little reporting in the literature on laser-cladded AISI 420 SS coatings [3][4][5][6][7]. For instance, Krakhmalev et al [3] investigated the thermal cycling by numerical simulation and the in-situ microstructural evolution by an experiment with AISI 420 SS prepared by a selective laser melting (SLM) technique.…”

“…For instance, Krakhmalev et al [3] investigated the thermal cycling by numerical simulation and the in-situ microstructural evolution by an experiment with AISI 420 SS prepared by a selective laser melting (SLM) technique. Zhang et al [4] studied the heat transfer process of the laser-cladded AISI 420 with 4% Mo, and the erosion and corrosion resistance of the laser-cladded AISI 420/VC metal matrix composites [5]. In order to improve the properties of the laser-cladded AISI 420 SS coating, Alam et al [6] explored the effects of the post-cladding heat treatment (PCHT, 565 • C for 1 h) on the micro-hardness variation and residual stress of laser-cladded specimens.…”

Microstructure and Electrochemical Corrosion Behaviors of Laser‐Cladded 2205 Duplex Stainless Steel

“…Laser cladding, one of the most promising techniques for surface modification, uses a high‐energy‐density laser beam to rapidly melt a metal powder and form a cladded layer (CL) with good metallurgical bonding to a substrate . Laser cladding can improve the surface performance of materials by imparting extremely high wear and corrosion resistances to a substrate surface.…”