Effect of laser heat treatments on the hardness of tool steels

Abstract

The application of laser heat treatments (LHT) has been growing attention in the last years, due to the effectiveness of localized hardening that can improve the tribological properties of steels. AISI P20 mod. steel is commonly used for plastic injection moulds applications and can be heat-treated to achieve high hardness values. This work presents an experimental investigation on the laser local heat treatments effect on the hardness of AISI P20 mod. steel parts, using a high-power diode laser. Different heat treatments at 1060 °C and 1100 °C using a feed rate of 10 mm·s-1 and 15 mm·s-1 were applied on the steel. The LHT were assessed through the hardness mapping trough depth and width. The results showed that the hardness of as-received P20 mod. tool steel is approximately 300 HV, and after LHT occurred an increment to around 625 HV with a fair hardness distribution. LHT had a minimum of 0.8mm and a maximum of 1.0mm depth.

Effect of Heat‐Treatment and NiB–TiO2 Composite Coating on the Tribological Performance of AISI P20 Steel

“…These processes typically involve heating the surface of AISI P20 steel or depositing a thin film onto the mold surface. Laser processing methods, [2,[20][21][22][23][24][25] plasma/ gas nitriding, [22][23][24][25][26] electrical discharge machining, [27][28][29] laminar plasma jet, [14] boronizing, [30][31][32] carburization, [31,33] and physical vapor deposition (PVD) coating, [5,6,9,34] are the most common techniques used to minimize, as much as possible, the failure at mold surface made of prehardened AISI P20 steel.…”