Organization And Properties Researchonthe Fe-0.5C-16Cr TIG Cladding

In actual production,hot-work dieoften failure because of wearing,in high temperature,surface of hot-work die is easily soften and oxidized,the dies therefore scrapped,seriously affecting productivity,increasing the cost of production.This paper is based on the failure characteristics of hot-work die,using orthogonal experiment,Fe-based 5Cr16 high-chromium alloy were prepared on Q235 and H13steel substrate by TIG cladding,microstructure,coating hardness,tempering resistance,high temperature tempering resistance and other properties were studied.The results have shown that the moldability of high-chromium alloy coating prepared on Q235 is good,no obvious cracks in the coating.The organization is composed of high-chromium austenite grains,black mesh carbide along the grain boundaries and carbide punctate distributed within the grains.The main phasesof orthogonal control group cladding F10 contained Cr-containing carbide Cr₇C₃,Cr₂₃C₆,Mo-containing carbide MoC,solid solution[Fe,Ni],Cr₂Fe₁₄C formed by Fe,Ni,C and Cr,it also contained carbide Fe₇C₃.After adding appropriate amount of alloying elements Mo,W,Si,special carbide W_1-3C also appeared in orthogonal experimental group.Hardness of orthogonal group coating are higher than F10,the hardness of coating F3 is the biggest,which reached440 HV_0.1,approximately 18%of F10.Analysis have shown that the influence of coating hardness of Mo and W is less than Si and they are close to each other.After 700? tempering,coating showed the ability of resistance high temperature temper softening.F6 coating has the maximum tempering hardness(593HV_0.1),which is about 1.4 times of F10,F1 coating has the minimum of tempering hardness?494 HV0.1?,which is only 1.1 times the F10.The coating high temperature temper hardness gradually increased with the increase of W,Si content,thetempering hardness first rise than decreased with the increase of Mo content,the optimal coating of orthogonal group should have high hardness and the strongest resistance of high temperature temper softening,thereby obtaining optimal formula coating F11?5Cr16-4.5%W-1%Mo-3%Si?.The high temperature oxidation resistance of F5,F7,F10 and H13 steel were tested in 600?and 700?,the high temperature oxidation resistance of F5 and F7coating are superior to F10 and H13 steel.After 600?oxidation,The per unit areaoxidation weight of F5(1.3181×10^-6g/mm²)is slightly less thanF7(1.3665×10^-6g/mm²),which is 17%and 65%of H13 steel and F10.Their high temperature oxidation resistance is the best.From F11's high temperature oxidation test,we found that it's high temperature oxidation resistance is similar with coating F5,after oxidation in 600?and 700?,The per unit areaoxidation weight of F11 is 6%and17%of H13 steel respectively.Conduct slurry abrasion test with test samples F7,F10,F11 and standard sample H13 steel.The results have shown that the abrasive resistanceof F7,F10 and F11 is better than H13 stee,has the highest relative wear resistance,which is 2.21 timesof H13steel,the highest relative wear resistance of F7 is lower than F11,which is 2.19timesof H13steel.The morphology of F11 abrasion test sample was observed,there are not only pit in some area cause by peeling,but also distinct furrow cause by sand formed scratch.The F11 coating was preparedon H13 steel with bright metallic luster and good shape,no cracks or holes and other defects.The hardness of F11 coating increased from bottom to top along the gradient direction,the average hardness of the layers are468 HV_0.1,495 HV_0.1 and 511HV_0.1.After 700?tempering,the tempering hardness of F11 is 615 HV_0.1,which is about 2.3 times of H13 steel.