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SUS30 4钢盐浴歧化反应渗铬后炉冷 ,渗层由碳化物、α相 (Fe Cr)和弥散分布的粒状σ相组成 ,无显微裂纹 ;基体晶界碳化物呈网状分布。水冷可抑制基体中的碳化物及渗层σ相的形成 ,但使渗层出现显微裂纹。空冷时基体晶界碳化物析出较少 ,渗层无显微裂纹 ,而且渗层中的σ相粒径比较小。渗铬炉冷后的试样经 10 50℃固溶处理 ,基体晶界网状碳化物及渗层中的σ相消失 ,但渗层碳化物增多且向表层富集 ,渗层的铬浓度和硬度均随固溶加热时间的延长而下降
SUS304 steel bath salt bath disproportionation chromizing furnace after cooling, the infiltration layer consists of carbide, α phase (Fe Cr) and dispersed distribution of granular σ phase, no micro-cracks; matrix grain boundary carbide network distribution. Water cooling suppresses the formation of carbides in the matrix and the σ phase of the coating, but causes microcracks in the coating. Air-cooled matrix grain boundary carbide precipitation less, no microscopic cracks, and the osmotic σ phase particle size is relatively small. After cooling the sample, the σ-phase disappeared in the matrix grain boundary carbides and the infiltrated layer, but the carbides in the carburizing layer increased and enriched to the surface layer. The chromium concentration in the carburizing layer and The hardness decreases with the prolongation of solution heating time