Making composite steel higher strength and higher ductility via introducing carbon diffusion strategy

Researchers have always aimed to break the trade-off relationship between strength and ductility. In this study, a carbon diffusion strategy was provided to improve the strength and ductility of composite martensite steel simultaneously, as well as increase uniform ductility by 190%. The process strengthens the martensite without losing the hardening ability of austenite constituents and brings in a substantial transition layer. This strategy can also be applied to other composite alloys with light elements, thus providing a pathway for making high-strength and high-ductility materials. IMPACT STATEMENT An element diffusion strategy was provided, breaking the rule of averages and making composite martensite steel exhibit a higher strength and ductility than the monolithic martensite steel.