Direct laser deposition of 304 stainless steel for surface enhancement of ASTM A36 steel

• Main Author: Zhang, Xinyi
• Other Authors: Zhou Wei
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/162151
• Institution: Nanyang Technological University

Direct laser deposition technology has the advantages of rapid prototyping, flexibility, and controllability when compared to traditional technologies. This technique uses the laser as a heat source and can process many difficult-to-process materials. DLD technology thus has a significant impact on the fields of surface strengthening and restoration. In this work, direct laser deposition of 304L stainless steel for surface strengthening of ASTM A36 steel was investigated. Compared with A36 steel, 304L stainless steel has better corrosion resistance and oxidation resistance. Therefore, cladding 304L stainless steel on ASTM A36 steel can enhance the surface properties of the substrate, and this study has certain guiding value for laser cladding of other materials. This study was mainly divided into the following steps: First, different DLD process parameters were used to deposit 304L stainless steel powder on the surface of A36 steel. The second step is to prepare the metallographic sample. Third, examine the sample's morphology and microstructure to ascertain its microhardness. Finally, it was determined how different parameters affected the morphology, microstructure, and microhardness of the cladding layer. The results demonstrate that varied laser power, powder flow rate, and laser scanning rate have an impact on the height, width, and depth of the cladding layer, and that the cladding layer's microstructure is clearly discernible. The microhardness variation law of the cladding layer was then examined in relation to the microstructure traits and process parameters of the cladding layer.