The effect of double austenitization on the microstructure and toughness of AISI M2 high speed steel

In this study, the effect of double austenitization on microstructure and toughness of AISI M2 high speed steel was investigated. For double austenitization treatment, the specimens, which are hardened initially at 1220 degrees C and quenched in air, were hardened for a second time in the temperature range 1150 - 1050 degrees C. For comparison purposes, another set of specimens is austenitized singly in the temperature range 1150 - 1050 degrees C. Tempering process was carried out between 500 - 640 degrees C. A double austenitization causes a fine carbide precipitation in the matrix, having sizes in the range of 0.10 +/- 0.05 mu m and volume fractions of between 1 and 6%. It is shown that a double austenitization treatment causes a decrease in fracture toughness (K-Ic), when compared with single austenitized ones. The reason for the lower K-Ic Values of double austenitized specimens are attributed to these fine carbide precipitates: It is suggested that they limit the plastic deformation capability of the matrix and yield lower fracture toughness values.


Ögel, Bilgehan (1990-01-01)
In this study, the relation of crack initiation and propagation to microstructure was shown in an AISI M2 high-speed steel using Vickers hardness indentation. Observations were carried out on the cracks generated from the corners of the square pyramid indentation in both the as-quenched, the quenched and tempered specimens. It is shown that cracks are nucleated from the corners of the indentation by either cleavage of the carbide or by decohesion between the carbide and the matrix, depending on the size o...
Effects of SiC particulates on the fatigue behaviour of an Al-alloy matrix composite
Kaynak, Cevdet (2006-01-01)
In this study, the fatigue behaviour of aluminium matrix-silicon carbide (SiC) particulate reinforced composite specimens was investigated in comparison to the matrix aluminium alloy containing 12 wt% Si. Three different weight percentages of SiC particulates: 5, 10, and 15 in the size range of 40-60 gm were injected into the melt. Mg was also added to improve the wettability of Al-alloy matrix over SiC particulates resulting in better interfacial bonding. Test specimens were machined from squeeze casting b...
The influence of cyclic fatigue damage on the fracture toughness of carbon-carbon composites
Ozturk, A (1996-01-01)
The influence of cyclic loads on the fracture toughness of a tightly woven carbon-carbon composite was investigated as a function of stress levels. Results of fracture toughness tests were correlated with microstructural examination using scanning electron microscopy (SEM). Values for the stress intensity factor, K-Ic, were determined using the ASTM single-edge notched bend test. Results were discussed in terms of the effects of applied cyclic stress levels and the relationship of the load-displacement curv...
The effect of austempering parameters on impact and fracture toughness of din 35nicrmov12.5 gun barrel steel
Aksu, Engin; Atala, Haluk; Department of Metallurgical and Materials Engineering (2005)
In this study the effects of different austempering times and temperatures on impact toughness, hardness and fracture toughness properties of 35NiCrMoV12.5 gun barrel steel are investigated. 300 °C, 325 °C and 350 °C were chosen as austempering temperatures. Isothermal holding times at these temperatures were chosen as 1 minute, 10 minutes, 1 hour and 10 hours. It was found that, 350 °C being an exception, austempering temperature and impact toughness has an inverse relationship and impact toughness increas...
Yurdakul, Kıvanç; Gürbüz, Rıza; Department of Metallurgical and Materials Engineering (2022-2-04)
In this study, the influence of defects that are occurred in manufacturing operations of filament wound composite overwrapped pressure vessels on burst pressure is investigated experimentally. Firstly, material characterization methods such as tensile testing and fiber volume fraction testing of carbon/epoxy composite specimens are completed. Following determining of different layer configurations for small scale composite pressure vessels, manufacturing and burst testing of vessels are accomplished. Ef...
Citation Formats
B. Ögel, “The effect of double austenitization on the microstructure and toughness of AISI M2 high speed steel,” STEEL RESEARCH, pp. 247–252, 1998, Accessed: 00, 2020. [Online]. Available: