The effects of laser-assisted heat treatment on warm formability of dual-phase materials

Abstract

ABSTRACT In this study, the effects of local heat treatment using a low-power laser on the bending formability of DP800 sheet material were experimentally investigated. In the first step of the study, only the punch contact bending region of sheet metal was locally heated with a constant feed rate (1 mm s−1) and at different laser powers (50, 75, and 100% Watt). In the next step, the sheet material was transferred to the bending die for bending without any cooling process, and into the last stage, the sheet material was formed in different angled V-bending dies (30°, 60°, and 90°). It was observed that in heating up to 75-W power, the hardness decreased to 237 HV due to the dissolution of the martensite in the microstructure of DP material, and the springback value decreased by 39.285% due to the decrease in hardness.