Microstructure And Properties Of Direct Laser Deposited 2Cr13 Stainless Steels

Martensitic stainless steels are known as high strength,hard and tough alloys with a fair corrosion resistance and are suitable for high plasticity,stress and impact load parts such as turbine and compressor blades.The application of the marine environment is also increased.As the flowing-passed component is often subjected to cavitation erosion,erosion wear,and corrosive corrosion etc.The service environment is harsh which reduced the service life of the stainless steel parts and caused great economic loss.Direct Laser Deposition(DLD)technology use high energy laser to scan the metal powder layer by layer to form the high performance metal materials or their parts with complex shapes.The microstructure prepared by DLD was refined through rapid solidification in the process.DLD can also realize the composition design of a material by control the addition of alloying elements.In recent years DLD was applied in the repair of stainless steel parts and their direct forming.In this paper,2Crl3 martensitic stainless steel bulk material was prepared by DLD and the alloy element effects on its wear and corrosion resistance were studied.The microstructure,wear and corrosion of the stainless steel by DLD were analyzed.In this study,2Crl3,2Crl 3-Mo and 2Crl3-CeO2 were deposited by DLD.The structure,properties and preparation mechanisms of the samples were studied by using means of metallographic microscope,scanning electron microscopy,transmission electron microscopy,XRD,hardness,friction and wear and electrochemical analysis methods.The best deposition process parameters of 2Crl3 stainless steels are power 1800W,scanning speed 5mm/s.In the optimization of the process parameters of prepared size is 20mm x 15mm x 10mm 2Crl3 and on the basis of 2Crl3 add stainless steel with Mo and CeO2 bulk materials 2Crl3-Mo 2Crl3-CeO2,density of about 96%.The microstructure of the 2Crl3 sample prepared by DLD is more fine than that of the conventional casting or forging process,and its hardness is around 470HV.The 2Crl3-Mo and 2Crl3-CeO2 samples are finer than the non-alloyed element,and the carbide of the grain boundary is finer.With the increase of Mo content of alloying elements,the hardness increased gradually,2%Mo sample hardness value is about 640HV.The wear resistance of the samples is gradually increased,the corrosion increased first and then decreased,containing 1.0%Mo sample wear and corrosion resistance is better integrated.With the increase of CeO2 content of alloying elements,hardness,wear resistance and corrosion resistance increased first and then decreased,in 1.2%CeO2 hardness of the samples containing the highest value is about 550hv.At the same time,the wear resistance and corrosion resistance of the synthesis of the best.