Effect of dilution rate on microstructure and hardness of laser cladding layer
In order to explore the influence of dilution ratio on the microstructure and hardness of cladding layers under different carbon steel matrix,316L stainless steel cladding layers with differ-ent dilution ratio were prepared on the surfaces of Q235,35 and 45 steel substrates by laser clad-ding technology,and the microstructure and hardness of cladding layers were characterized by la-ser confocal microscope,scanning electron microscope and Vickers hardness tester.The experi-mental results showed that the dilution rate of cladding layer increased with the increase of laser power,and the matrix difference would have a certain influence on the dilution rate of cladding layer under the same laser power.The cladding layer and the matrix were metallurgically bonded,the elements of the cladding layer and the nearby matrix tended to be consistent with the increase of dilution rate,and the bonding effect was enhanced,at the same time,the increase of C element content in the cladding layer had a dispersion strengthening effect.The dilution rate of cladding layer was over 30%,and the microstructure characteristics of rapid solidification gradually disap-peared,and the cladding layer changed from austenite to martensite,and the hardness value in-creased by 250~300 HV.