ABSTRACT

Metal injection molding (MIM) is a technique for fabricating metallic parts of complicated shapes, and 17-4PH stainless steel is one of the most effective materials in resistance to corrosion. The microstructural evolution of 17-4PH stainless steel added with VN at different amounts is investigated for MIM specimens, and the micro-hardness, wear coefficients, and wear losses of these specimens had been characterised. After heat treatment, martensite, austenite and ferrite existed for specimens added with VN and segregation of VN is observed as the addition increased to 8wt%. Compared with MIM 17-4PH stainless steel, the hardness of the specimens increased with VN. The sintered specimens exhibit a decrease in friction coefficients and an increase in the running-in period with VN. The wear loss and wear scars width of the specimens decrease with VN. The specimens with VN are more wear-resistant and the specimens with 12wt% VN yield the least wear loss among all the specimens. Heat treatment is beneficial to improve wear resistance of the specimens.

摘要

金属注射成型（MIM）是一种制造复杂形状金属零件的技术，17-4PH不锈钢是最有效的耐腐蚀材料之一。研究了添加不同量 VN 的 17-4PH 不锈钢 MIM 试样的显微组织演变，并表征了这些试样的显微硬度、磨损系数和磨损损失。热处理后，添加 VN 的试样存在马氏体、奥氏体和铁素体，当添加量增加到 8wt% 时，观察到 VN 偏析。与MIM 17-4PH不锈钢相比，试样的硬度随着VN的增加而增加。烧结试样的摩擦系数降低，VN 的磨合期增加。试样的磨损量和磨痕宽度随 VN 的增加而减小。含有 VN 的试样更耐磨，含有 12wt% VN 的试样在所有试样中产生的磨损损失最少。热处理有利于提高试样的耐磨性。