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

Microstructure and Properties of a Novel Carbon‐Martensitic Hot Work Tool Steel Processed by Laser Additive Manufacturing without Preheating

“…Analogously to other L-PBF-processed steels, the subgrain structure is accompanied by microsegregation in the interdendritic spaces, as determined by EDS measurements (Figure 4c-f ). [18,19] These findings are well in line with solidification simulations following the Scheil-Gulliver approach (Figure 5), which predict the enrichment of the remaining melt in Cr and Mo upon solidification. In the applied Scheil-Gulliver approach, diffusion of elements in the already solidified material is neglected completely, whereas an infinitely fast diffusion is assumed in the liquid material.…”

“…Thus, the cold crack susceptibility of the steel appears to be reduced compared to similar hot work tool steels, such as AISI H13, which often reveal significantly larger cracks after L‐PBF. [ 18 ] As the occurring cracks in the L‐PBF specimens are scattered throughout the specimen volume, and no macroscopic cracks exist, the crack formation is likely associated with the particular local thermal conditions acting around isolated hatches. Although the number and size of the cracks are low compared to other PBF‐LB/M‐processed tool steels, they might influence the mechanical properties of the material due to local stress enhancement and facilitated material failure, especially under cyclic loading conditions.…”

Influence of Cell Structure on Yield Strength and Strain‐Hardening Behavior in Additively Manufactured H13 Hot Work Tool Steel

“…The retained austenite has been reported to remain in AMH with arrangement along building direction or cell structure. [ 6,31–33 ] In contrast, the hierarchical structure of martensite leading to PAG–packet–block was detected in CMH (Figure 6e). The average martensite grain size in AMH was 3.1 μm, which was smaller than the grain size of 5.3 μm in CMH.…”