Microstructure Evolution and Mechanical Properties of AISI 430 Ferritic Stainless Steel Strengthened Through Laser Carburization

Abstract

Carburization assisted by laser processing is a promising method to strengthen metallic materials. Direct laser beam carburization is implemented for the first time on thin AISI 430 ferritic stainless steel sheets with graphite coating under different conditions. Microstructural morphology, phase constitution, carbon content, microhardness and tensile behavior are investigated to evaluate laser carburization effect. The carburized zone presents different morphologies according to linear energy density of laser beam. The least carbon content is around 0.4 wt% in the carburized zone where austenite becomes the leading phase. Delta ferrite is found in cellular carburized area, which resembles to a duplex microstructure. Hardness of carburized zone has been at least increased by 130%. And the yield strength and ultimate tensile strength of a fully carburized sample can be increased up by respectively 90% and 85 %. This hardening effect is driven by the precipitation of carbides formed during solidification offering pinning points for dislocations and grain boundaries. These improvements could be useful to modify locally ferritic stainless steel to meet industrial needs such as wear-resistant surface.

Corrugation Reinforced Architectured Materials by Direct Laser Hardening: A Study of Geometrically Induced Work Hardening in Steel

“…[ 42 ] Localized laser heat treatment is a promising advanced processing route for creating architectured materials. [ 43–46 ]…”

“…[42] Localized laser heat treatment is a promising advanced processing route for creating architectured materials. [43][44][45][46] To the knowledge of the authors, no published work has explored the mechanical behavior of laser-architectured corrugated materials by both experimental and computational approaches. The aim of this work is to further our understanding of the mechanics of corrugated architectured materials and the beneficial effect on necking strain induced by corrugated reinforcement.…”