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采用等离子束和激光表面合金化对灰铸铁表面进行强化。利用三点弯曲试验测试合金化层抗弯性能,采用金相显微镜、显微硬度计、SEM和XRD等仪器对其微观组织、硬度断口形貌和相组成进行分析。研究结果表明:灰铸铁等离子束表面合金化层由奥氏体和莱氏体组成,而激光合金化层几乎全部为奥氏体。在相同功率密度下,采用等离子束表面合金化处理后的合金化层较厚;合金化层的硬度最大值均为次表面;Fe_3C和Cr_7C_3的存在使得等离子束合金化层的硬度比激光合金化层高;等离子束合金化层断裂方式为解理断裂,而激光合金化层为韧性断裂。
The gray cast iron surface is strengthened by plasma beam and laser surface alloying. The three-point bending test was used to test the flexural properties of the alloyed layer. The microstructure, fracture morphology and phase composition of the alloyed layer were analyzed by metallographic microscope, microhardness tester, SEM and XRD. The results show that the surface alloying layer of gray cast iron plasma beam consists of austenite and ledeburite, while the laser alloying layer is almost austenite. At the same power density, the alloying layer after plasma beam surface alloying treatment is thicker. The maximum hardness of the alloying layer is sub-surface. The existence of Fe 3 C and Cr 7 C 3 makes the hardness of the plasma beam alloy layer more than laser alloying Layer height; plasma beam alloying layer cleavage fracture cleavage, and laser alloying layer is ductile fracture.