[T20] Materials Characterization of AM Materials

[14D-T20-04] Determining Suitable Processing Parameters to Produce AISI 420 Stainless Steel Using Laser Powder Bed Fusion

*M. Sepako¹, T. Mkhaliphi¹, D. Blaine¹ (1.Stellebosch University, South Africa)

Keywords:Laser powder bed fusion, AISI 420 stainless steel, Processing parameters , Microstructure

Processing parameters such as laser power, scan speed and hatch spacing influence the microstructure and material properties of parts produced using laser powder bed fusion (L-PBF). The study investigated the effect of L-PBF on the microstructural and mechanical properties of as-built AISI 420 stainless steel through controlled variations in processing parameters. The methodology centers on investigating how energy density and laser power influences part density, porosity, microstructure, and mechanical properties in the as-built samples. The preliminary results indicated that energy density values ranging from 79.4 to 136.6 J/mm³ with a minimum laser power of 150 W resulted in relative density exceeding 99 % with porosity levels below 0.01 % with average pore size of 30 µm. The micro-hardness of the samples ranged between 540 HV and 639 HV surpassing cast steel hardness. The microstructure displayed martensitic laths and XRD analysis confirmed the presence of retained austenite phases.