Microstructure evolution and hardness of S30C carbon steel produced by powder bed fusion using an electron beam and subsequent heat treatments

The microstructure and hardness of S30C carbon steel fabricated via powder bed fusion using an electron beam (PBF-EB) and the influence of subsequent heat treatments were firstly investigated. The microstructure of as-built S30C, comprising ferrite and pearlite with an amount of dislocations. The microstructure and hardness showed a height-dependent relationship along building direction. The quenched sample showed lath martensite with maximum hardness (HV 643 ± 18), which transformed to tempered martensite after further tempering. This study provides a research basis for the application of PBF-EB technology in the development of high-performance carbon steel.