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在45钢基体上进行了堆焊试验,并将堆焊后的试样分别进行了直接空冷和焊后回火处理,研究了这两种焊层的显微组织、硬度以及耐磨性能。试验研究结果表明:堆焊后空冷试样的显微组织为粗大的板条状马氏体和大量残留奥氏体;堆焊后进行500～550℃回火处理,试样焊层的显微组织主要是细小托氏体和少量残留奥氏体。堆焊后回火处理试样的硬度比直接空冷试样的硬度低10%,邻近熔合区的基体硬度有所提高,熔合区硬度梯度减小,有利于改善堆焊层的韧性;焊后回火处理的试样的耐磨性比直接空冷试样的耐磨性提高35%。
The surfacing welding test was carried out on the 45 steel substrate. The samples after welding were directly air-cooled and post-weld tempered respectively. The microstructure, hardness and wear resistance of these two kinds of welding layers were studied. The experimental results show that the microstructure of the air-cooled specimens after welding is coarse lath martensite and a large amount of retained austenite. After surfacing, tempering is performed at 500-550 ° C, Tissue is mainly small and small amount of retained austenite. The hardness of the sample after tempering was 10% lower than that of the direct air-cooled sample, the hardness of the substrate near the fusion zone was increased, and the hardness gradient of the fusion zone was reduced, which was good for improving the toughness of the surfacing layer. The wear resistance of the fire-treated specimens is 35% higher than that of the direct air-cooled specimens.