Research Of Corrosion Resistance Of H13Steel Produced By Re-N-C-V-Nb Compound Deposition Process

H13steel was widely used as die material in aluminum alloy extrusion industry for its excellent combination property. It is found that corrosion is one of the reasons that lead to initial failure such as wear, spallation and thermal fatigue in aluminum alloy extrusion die. The service life of aluminum alloy extrusion die can be prolonged by enhance the corrosion resistance of H13steel. This paper using carbonitriding sample and quenching&tempering sample as reference, choosing3.0wt%NaCl solution,4.0wt%NaOH solution and0.50wt%NaHSO4solution as corrosion media with4different pre-immerse time, study the corrosion resistance of V(C, N)&Nb(C, N) compound layer.With the help of electrichamical technic and SEM technic, the results can be getting as the follow:(1)During the3.0wt%NaCl solution, the corrosion rate of compound deposition sample is first rasing than falling with the pre-immerse time prolong.While the carbonitriding sample and quenching&tempering sample is rasing. After4days’pre-immerse, the corrosion rate of compound deposition sample, quenching&tempering sample and carbonitriding sample is0.012152mm·a-1,0.05253mm· a-1and1.4452mm· a-1respectively, the surface appearance is cover by compact corrosion products, unsound corrosion products with pitting ejecta and complete break. These means that compound deposition sample has the lowest corrosion rate and the best corrosion resistance in Cl’ media.(2)During the4.0wt%NaOH solution, the corrosion rate of compound deposition sample and the quenching&tempering sample are falling with the pre-immerse time prolong.While the carbonitriding sample is rasing. After4days’ pre-immerse, the corrosion rate of compound deposition sample, quenching&tempering sample and carbonitriding sample is0.021128mm· a-1,0.07450mm· a-1and6.3725mm· a-1respectively, the surface appearance is cover by thick corrosion products, unsound corrosion products with some pitting ejecta and surface layer upwarping and spalling. These means that compound deposition sample has the lowest corrosion rate, so it has the best corrosion resistance in OH-media.(3)During the0.50wt%NaHSO4solution, the corrosion rate of all three kinds of sample are raising with the pre-immerse time prolong. After2hours’ pre-immerse, the corrosion rate of compound deposition sample, carbonitriding sample and quenching&tempering sample is0.021128mm· a-1,0.07450mm· a-1and6.3725mm· a-1respectively, the surface appearance is localuniform corrosion, cover by leather-like corrosion products and cover by broken corrosion products. These means that compound deposition sample has the lowest corrosion rate, so it has the best corrosion resistance in H+media. The above result reveal that the compound deposition sample has more lower corrosion rate than carbonitriding sample and quenching&tempering sample, it means that the compound deposition sample has a higher corrosion resistance during the H+, OH-, Cl-media.