以渗铝为主的Q195钢交流电场增强粉末法铝铬共渗特性

在渗铝剂中加入铬粉,对Q195钢在800 ℃进行以渗铝为主的交流电场增强及常规粉末法铝铬共渗。用金相显微观测、X射线衍射分析、显微硬度测试等分析渗层组织、相、厚度及显微硬度沿渗层深度方向的分布。结果表明,相较单一渗铝,添加少量铬粉对常规铝铬共渗层组织和厚度影响不大,但次表层硬度提高;交流电场对单一渗铝和铝铬共渗均有促渗作用,较单一渗铝,添加微量铬粉进一步加快渗速,但对次表层硬度影响不大,随渗剂中铬粉含量增加,渗层厚度先增后减,添加0.1%铬粉时促渗效果最为显著,所得渗层厚约123 μm,而交流电场单一渗铝层厚约50 μm,常规单一渗铝层厚仅约18 μm。

Characteristics of alternating current field enhanced aluminizing-based pack chrom-aluminizing on Q195 steel

Alternating current field enhanced pack chrom-aluminizing (ACFPCA) and the conventional pack chrom-aluminizing (CPCA) at 800 ℃ on the surface of the Q195 steel specimens were carried out, respectively, in which the inward diffusion of aluminium dominated, and then adding chromium powder to the aluminizing agent. The layer structure, phase, thickness and distribution of microhardness along the depth direction of the layer were studied by means of metallographic microscopic observation, X-ray diffraction analysis and micro-Vickers hardness test. The results show that compared with single aluminizing, adding a small amount of chromium powder has little effect on structure and thickness of the CPCA layer except increasing the hardness of the subsurface layer. Alternating current field (ACF) promotes both aluminizing and chrom-aluminizing. Compared with single ACF enhanced pack aluminizing (ACFPA), the inward diffusion of Al is further accelerated by adding a small amount of chromium powder to the aluminizing agent in ACFPCA. However, adding a small amount of chromium powder has little effect on increasing the hardness of the subsurface. With the increase of chromium powder in the pack agent, the ACFPCA layer's thickness increases first and then decreases. When 0.1% chromium powder is added, the promoting effect is the most significant and the obtained layer is about 123 μm thick, while the thickness of the ACFPA layer is about 50 μm and that of CPA layer is only about 18 μm.