Selective laser melting (SLM) was successfully applied to fabricate strong and ductile reduced activation ferritic/martensitic (RAFM) steel by introducing heterogeneous multi-/bimodal microstructure. The SLM-built RAFM steel exhibited an excellent combination of strength and ductility (i.e. yield strength of 1053 ± 4.7 MPa and elongation of 16.9 ± 0.4%), well surpassing the previously reported counterparts. The superior strength was expected from the refined grains and lath martensites, and the high ductility was associated with the improved dislocation-controlled strain hardening capability. This work provides a basis for developing high-performance RAFM steel by microstructural design via SLM.

通过引入异质的多/双峰微观结构，选择性激光熔化（SLM）成功地应用于制造强度高且韧性降低的活化铁素体/马氏体（RAFM）钢。用SLM制造的RAFM钢表现出强度和延展性的极佳组合（即屈服强度为1053±4.7 MPa，伸长率为16.9±0.4％），远远超过了先前报道的同类产品。预计细晶粒和板条马氏体的强度更高，而高延展性与位错控制的应变硬化能力的提高有关。这项工作为通过SLM通过微结构设计开发高性能RAFM钢提供了基础。