Round Robin Study Evaluating Consistency of 4340 Steel Specimens Manufactured by Different Laser Powder Bed Fusion Machines

Development of powder bed fusion – laser beam process for AISI 4140, 4340 and 8620 low-alloy steel

“…Additionally, there are generic issues during PBF-LB (e.g. keyholes pores and lack of fusion defects) that can lead to a reduction in performance when compared to conventionally produced material and induce anisotropic behaviour [5][6][7]. Overall, these issues have put into question the viability of martensitic low-alloy steel when using PBF-LB.…”

“…In order to adopt these alloys for PBF-LB, detailed process development is required in combination with mechanical property testing. To date, limited data on this subject is available in the literature, with process development of martensitic low-alloy steel primarily involving single-track experiments [8][9][10] and the production of specimens at specific sets of processing parameters [6,7,11,12]. An important parameter that has yet to be examined in adequate detail is the build plate preheating temperature (BPT), which has improved the processing of carbon-containing tool steels during PBF-LB [13][14][15].…”