Influence of different surface treatments of H13 hot work die steel on its thermal fatigue behaviors

Abstract

Thermal fatigue checking is the general failure of hot work die steels, which is relative with the structures and properties of the steels and the stress alternated during the employment. The Uddeholm test method on thermal fatigue is used to compare the behaviors of different samples, which are treated with plasma nitriding,plasma sulfur-carbon-nitriding,boronizing or not treated. The results show that the nitriding improves the thermal fatigue property of the tool steel, while the plasma sulfur-carbon-nitriding and the boronizing impair the property. The mechanisms are induced as follows. By increasing the hardness and changing the stress distribution in the surface layer, surface treatment can decrease the plastic deformation and the tensile stress during the cycling. Therefore, the generation and growth of the cracks are restrained. On the other hand, as results of surface treating, in the surface layer the toughness declines and the expanding coefficient ascendes; the latter change caused the strengthening of the tensile and compressive stress during the cycling. Thus the resistance to thermal fatigue is weakened. Whether or not the surface treatment is favor to thermal fatigue of tool steels relies on which factor is dominant.

Geometry Analysis and Microhardness Prediction of Nickel-Based Laser Cladding Layer on the Surface of H13 Steel

“…Various surface treatment techniques are used to create a continuous compound layer and decrease the damage of crack, corrosion and erosion, such as quenching, physical vapour deposition, chemical vapor deposition process, laser cladding, etc. [4,6,7].…”

Thermal fatigue evaluation of AISI H13 steels surface modified by gas nitriding with pre- and post-shot peening

“…Surface engineering of physical vapor deposition (PVD), nitriding, boronizing, etc. can decrease the damage of corrosion and wear on dies through the formation of the continuous compound layer, serving as effective isolating between the molten metal and dies surface [6][7][8][9][10][11]. Especially a few surface modification technologies are beneficial to improving the thermal fatigue resistance due to the enhanced surface hardness and induced residual compressive stress [9][10][11].…”

“…Min [7] and Pellizzari [14] demonstrated that a thinner and compact nitrided compound layer is expected to show the better thermal fatigue resistance behavior. Kundalkar [13] indicated that the thermal fatigue resistance decreased with the increase of phase ratio of ε-Fe2-3N and γ′-Fe4N in the nitrided layers.…”

The Use of 3D Scanning Methods to Evaluate the Hybrid Layer Used in Forging Tools in Order to Improve their Durability

“…For example, a comprehensive analysis of the major destructive mechanisms of tools in the forging process of car steering was presented in work [11]. In order to avoid those phenomena, various methods are used, which usually consist in producing or applying appropriate protective layers, the task of which is the protection from one or more destructive mechanisms [2,12].…”

“…Despite the fact that this method is well-known and well-mastered, it does not always provide a clear effect of durability improvement. That is why other methods are being searched for to improve tool durability in forging processes, which are more effective, yet more expensive as well [12,13]. The most recent methods include undoubtedly hybrid technologies, consisting in the use of two or more surface engineering techniques.…”