The effect of heat treatment on the mechanical, tribological and load-carrying properties of PACVD-coated tool steel

Thermodynamic Analysis of M₇C₃ Carbide Dissolution during Plasma Nitriding of an AISI D2 Tool Steel

“…steels which are hybrid processed should be emphasized. 8) Besides steel hardness, in-service integrity of coated parts depends significantly not only on the phases present at regions adjacent to steel surface but also on the surface roughness. [8][9][10][11] Both formation of nitrides and decomposition of carbides due to nitrogen absorption during plasma nitriding of alloyed steels have been reported.…”

“…8) Besides steel hardness, in-service integrity of coated parts depends significantly not only on the phases present at regions adjacent to steel surface but also on the surface roughness. [8][9][10][11] Both formation of nitrides and decomposition of carbides due to nitrogen absorption during plasma nitriding of alloyed steels have been reported. 1,[11][12][13][14][15][16][17] In particular, formation of iron nitrides, i.e., the compound layer, during plasma nitriding of diverse steels has been studied in depth.…”

“…[1][2][3][4][5][6][7][8] This two-stage process of nitriding plus hard coating deposition is normally known as either duplex or hybrid process. [1][2][3][4][5][6][7][8] Deposition of hard ceramic coatings onto both nitrided and non-nitrided steels is a potentially effective treatment for improving abrasive wear resistance. Although wear resistance near the surface of the coated part does not depend on substrate mechanical properties, tool's life is barely increased when the substrate is coated in the unhardened condition and high contact loads are applied.…”

Wear mechanisms and surface engineering of forming tools

“…49,50 In order to provide a high load-carrying capacity combined with a superior impact, a wear-resistant tool-steel substrate should have a hardness of at least 64-65 HRc and a fracture toughness above 12 MPa m 1/2 . 51 Although plasma nitriding provides the highest static load support, its negative effect on the surface ductility greatly reduces the resistance of the coated surface on the crack initiation and propagation, 52,53 as shown in Figure 12.…”

Impact of fracture toughness on surface properties of PVD coated cold work tool steel

“…Complete transformation of retained austenite into martensite, cryogenic aging and carbon clustering, and the precipitation of fine -carbides into the tempered martensitic matrix improve wear and fatigue resistance, and increase strength and hardness of the material [24]. When combining different vacuum heat treatment parameters and deep cryogenic treatment, residual stress field and hardness vs. fracture toughness ratio of tool steel can be further enhanced [25] and thus optimized depending on the tool requirements. This is especially important if tools are planned to be coated, where beside coating thickness, hardness and surface roughness, properties and surface structure of the substrate have significant effect on the wear behavior, load-carrying capacity and adhesion…”