Investigation of Heat Treatment Strategies for Additively-Manufactured Tools of X37CrMoV5-1

Abstract

For cost-intensive products like automobiles, clients often wish to personalize their product, what forces the industry to create a large diversity of combinable parts. Additionally, the life cycles of many components become shorter. For highly-stressable parts, which are commonly manufactured by forging, the short changeover cycles result in expensive products, as the costs of tools must be offset by the sale of only a few parts. To reduce the tool cost, new, flexible processes have to be established in tool manufacturing. Laser-based additive manufacturing is noted for its high flexibility; notably, Laser Metal Deposition (LMD) is gaining increasing relevance in research, as it is already used for coating and repairing forming tools, this technology makes it possible to add material onto free-formed surfaces. Therefore, investigations are being conducted to qualify this process to produce forging tools. Due to the thermal processes which are required during additive manufacturing, the microstructure of the material differs from that of wrought material. This, in turn, affects the strategy of post heat treatment in order that the required mechanical properties for tools be attained. Within this manuscript, the influence of additive manufacturing on performance characteristics of hot work tool steel X37CrMoV5-1 (1.2343) is analyzed. To investigate the behavior of additively manufactured material during the process chain of tool manufacturing, properties for different states of a heat treatment are characterized by hardness and strength. It was shown that the strength of the additively manufactured material could be increased compared to wrought material by using a tailored heat treatment. The effects that cause this behavior are investigated by comparing the microstructure at different states of heat treatment.

Investigations on Mechanical Properties of Lattice Structures with Different Values of Relative Density Made from 316L by Selective Laser Melting (SLM)

“…They are applied to build "ready-to-use" mechanical parts as well as tools (molds, dies, punches, etc.) [19,20]. Over the past few years, MAM methods have been used in the production of regular cellular structures [21][22][23][24] that demonstrate high energy absorption capacities with low relative densities [25][26][27][28].…”

Microstructural and Mechanical Evaluation of a Cr-Mo-V Cold-Work Tool Steel Produced via Electron Beam Melting (EBM)

“…High hardness together with high yield strength are significant properties for wear reduction in order to extend the tool life. EBM provides higher hardness than conventionally manufactured PM material after austenitization and quenching, which can be a result of fine-grained martensitic and dendritic microstructure that results from the high cooling rates characteristic to EBM and laser-based PBF-AM, as stressed by Junker et al [ 30 ]. The discontinuous carbide network was also considered to be the reason for the relatively high compression strength.…”

Residual stress in laser-based directed energy deposition of aluminum alloy 2024: simulation and validation

“…Namely, residual stress is any self-equilibrated stress system developed in a component in the absence of any externally applied load; indeed, as for any laser-based process [9], in DED, the formation of the residual stress is ascribed to rapid heating and cooling, due to focused energy. It has been already shown that untreated residual stress may induce fracture under loading and reduce the fatigue life and the mechanical properties of the repaired or coated part [10,11]; moreover, although proper heat treating can be performed to release the stresses depending on the metal alloy [12,13], deformations arising during the process may result in a mismatch with respect to the intended geometry and even compromise the product integrity [7,10] or the repair quality in general [3].…”