Abstract A hypoeutectic high chromium cast iron (HCCI) was fabricated by super-solidus liquid phase sintering (SLPS) technology with gas atomized powders as raw materials. The effects of sintering parameters on densification, microstructure evolution and mechanical properties of the alloy were investigated systemically. The results showed that samples with full density could be fabricated and sintering temperature window suitable for SLPS is around 20 °C. The X-ray diffraction (XRD) revealed that the hypoeutectic HCCI mainly consists of martensite matrix and M7C3 carbide as well as small amount of austenite, and optical metallographic analysis showed that M7C3 carbides are of crystal square bars with uniform distribution in the matrix. As sintering temperature or holding time is raised, both grain and carbide are gradually coarsen, while the strength and toughness of the alloy increase at first and then decline. The mechanical properties of sintered hypoeutectic HCCI in an optimized sintering process were of hardness HRC63, bending strength 2241 MPa, and impact toughness 8.0 J/cm2. A model about microstructure evolution in sintered hypoeutectic HCCIs has been proposed.

中文翻译：

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亚共晶高铬铸铁的烧结及其组织和性能

摘要 以气体雾化粉末为原料，采用超固相液相烧结（SLPS）技术制备亚共晶高铬铸铁（HCCI）。系统研究了烧结参数对合金致密化、组织演变和力学性能的影响。结果表明，可以制造出具有全密度的样品，适合 SLPS 的烧结温度窗口约为 20°C。X射线衍射(XRD)表明亚共晶HCCI主要由马氏体基体和M7C3碳化物以及少量奥氏体组成，光学金相分析表明M7C3碳化物呈方晶状，在基体中分布均匀。随着烧结温度或保温时间的提高，晶粒和碳化物均逐渐粗化，而合金的强度和韧性则先增加后下降。在优化的烧结工艺中烧结亚共晶HCCI的力学性能为硬度HRC63、弯曲强度2241 MPa和冲击韧性8.0 J/cm2。已经提出了关于烧结亚共晶 HCCI 中微观结构演变的模型。