A local heating method by near-infrared rays for forming of non-quenchable advanced high-strength steels

A forming process by local heating using near-infrared rays (NIRs) is proposed to reduce springback of non-quenchable advanced high-strength steels, such as dual-phase steels, that are not suitable materials for hot stamping. NIR lamps show outstanding cost performance, and the width of the heating area can be controlled by designed reflectors. To confirm the advantages of NIR local heating, DP980 sheets were heated by two methods – NIR local heating and furnace heating, which heats the whole material. V-bending and 2D-draw bending were conducted with heated DP980 sheets. Results showed that NIR local heating has advantages over furnace heating in both shape accuracy and hardness.