Production and Characterization of a Modified Hot Work Tool Steel by Laser Powder Bed Fusion

Conventional hot work tool steels with medium carbon content, fabricated by laser powder bed fusion (L-PBF), are susceptible to cracking. To reduce this risk, as in well-established welding process, usually preheating or in-situ heating needs to be applied. In order to address this issue, a modified grade, with lower carbon wt pct, is proposed to fabricate parts showing less susceptibility to cracking. The microstructure was studied in the as-built condition and after direct double tempering for 2 hours each at 625 degrees C and 650 degrees C. Tensile properties and hardness were compared with those of wrought and (L-PBF) processed AISI H13. The results confirm improved printing performance of the new steel grade and the possibility of achieving similar hardness and strength by proper tempering treatment.

Automated summary

By reducing the carbon content, the modified grade of steel shows improved performance in laser powder bed fusion manufacturing process, reducing the risk of cracking, and achieving similar hardness and strength through proper tempering treatment.