A review on spray-formed high-speed steels: process modeling, microstructure evolution, and mechanical properties

High-speed steels (HSSs) are widely used as cutting tools and wear-resistant parts due to their excellent hot hardness and wear resistance. It plays an irreplaceable role in industrial production. Over the past decades, many methods have been developed for manufacturing HSS components. Among these methods, spray-formed HSS avoids macro-segregation and forms uniform microstructures with fine equiaxed grains, which has high research value and broad application prospects. However, a comprehensive review of recent advances in spray-formed HSS is still lacking. A critical evaluation of the existing research is useful and this article aims to address this need. This paper reviews all the significant attributes of spray forming (SF) technology used for manufacturing HSS. It covers a comprehensive overview of the benefits of the SF process, theoretical model analysis, solidification sequence of HSS, carbide identification and morphology, mechanical properties and wear resistance of HSS. Some constructive suggestions and viewpoints are put forward for the existing problems and future prospects of SF.