Effect of High-Temperature Heating on Chemical Changes in M7C3 Carbides of AISI D2 Tool Steel (original) (raw)
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Effect of High-Temperature Heating on Chemical Changes in M7C3 Carbides of AISI D2 Tool Steel
International Letters of Chemistry, Physics and Astronomy, 2014
The paper presents the study results obtained on 16H12MF/NC11LV/D2 tool steel. The main purpose of the study was to establish the chemical composition of the coarse primary M 7 C 3 carbides occurring in that steel after a standard soft annealing. The effect of high-temperature annealing in the air atmosphere was investigated. The study was limited to the decarburized layer, on the distance of about 0.4 mm from the surface, of hardened steel after annealing and austenitizing at 1150 ºC in the air atmosphere for the periods of 30 and 90 minutes. It was found that the coarse primary M 7 C 3 carbides of the annealed D2 tool steel differ significantly as to the contents of Cr, Mo, and V, and in the most degree to the contents of chromium and molybdenum. The average concentration of chromium rises successively with the growth of austenitizing time. On the other hand, the concentrations of molybdenum and vanadium are lower after 30 minutes of austenitizing than their concentrations in the similar carbides of the annealed steel. Prolongation of the austenitizing time up to 90 minutes results in the increase of molybdenum and vanadium contents in the coarse carbides. It was found that austenitizing of AISI D2 tool steel at the temperature of 1150 ºC in the air atmosphere leads to precipitation of the second phase, brighter in the BSE_Z pictures, in relation to the matrix of carbides, with the amount and magnitude being higher with the annealing time.
Effect of High-Temperature Heating on Chemical Changes in M7C3 Carbides of AISI D2 Tool Steel
International Letters of Chemistry Physics and Astronomy, 2014
The paper presents the study results obtained on 16H12MF/NC11LV/D2 tool steel. The main purpose of the study was to establish the chemical composition of the coarse primary M 7 C 3 carbides occurring in that steel after a standard soft annealing. The effect of high-temperature annealing in the air atmosphere was investigated. The study was limited to the decarburized layer, on the distance of about 0.4 mm from the surface, of hardened steel after annealing and austenitizing at 1150 ºC in the air atmosphere for the periods of 30 and 90 minutes. It was found that the coarse primary M 7 C 3 carbides of the annealed D2 tool steel differ significantly as to the contents of Cr, Mo, and V, and in the most degree to the contents of chromium and molybdenum. The average concentration of chromium rises successively with the growth of austenitizing time. On the other hand, the concentrations of molybdenum and vanadium are lower after 30 minutes of austenitizing than their concentrations in the similar carbides of the annealed steel. Prolongation of the austenitizing time up to 90 minutes results in the increase of molybdenum and vanadium contents in the coarse carbides. It was found that austenitizing of AISI D2 tool steel at the temperature of 1150 ºC in the air atmosphere leads to precipitation of the second phase, brighter in the BSE_Z pictures, in relation to the matrix of carbides, with the amount and magnitude being higher with the annealing time.
Study of Carbide Evolution During Thermo-Mechanical Processing of AISI D2 Tool Steel
Journal of Materials Engineering and Performance, 2013
The microstructure of a cold-worked tool steel (AISI D2) with various thermo-mechanical treatments was examined in the current study to identify the effects of these treatments on phases. X-ray diffraction was used to identify phases. Microstructural changes such as spheroidization and coarsening of carbides were studied. Thermodynamic calculations were used to verify the results of the differential thermal analysis. It was found that soaking temperature and time have a large influence on dissolution, precipitation, spheroidization, and coalescence of carbides present in the steel. This consequently influences the hot workability and final properties.
Transformations of Carbides During Tempering of D3 Tool Steel
Journal of Materials Engineering and Performance, 2014
The studies were performed on D3 tool steel hardened after austenitizing at 1050°C during 30 min and tempering at 200-700°C. Based on the diffraction studies performed from the extraction replicas, using electron microscopy, it was found that after 120-min tempering in the consecutive temperatures, the following types of carbides occur:
Metals, 2019
Vanadis 10 steel is a powder metallurgy processed tool steel. The aim of the present study is to analyze the microstructural variation in this steel that takes place when the process variables related to the heat treatments of quenching and tempering are modified. Specifically, the destabilization of austenite, the precipitation of secondary carbides and the amount of retained austenite were analyzed. The research methodology employed was a Design of Experiments (DoE). The percentage and types of precipitated crystalline phases were determined by XRD, while the microstructure was revealed by means of SEM-energy-dispersive X-ray spectroscopy (EDX). The destabilization of austenite was favored by tempering at 600 °C for at least 4 h. These same conditions stimulated the removal of the retained austenite and the precipitation of M7C3 secondary carbides. For the precipitation of MC secondary carbides, it was necessary to maintain the steel at a temperature of 1100 °C for at least 8 h. T...
A Study of Carbide Precipitation in a H21 Tool Steel
ISIJ International, 2014
Carbide precipitation in a H21 tool steel during conventional heat treatment was studied. The aim of this work was to study the exact microstructure and for better understanding of carbide formation during double tempering process of the H21 tool steel. The steel was austenised either at 1 100°C or 1 250°C for 1 hour, and water quenched. Double tempering was performed at 650, 750 and 800°C for 1 hour with air cooling in the first and second temper for each austenising temperature. The results showed that the double tempered microstructure consisted of tempered martensite, lower bainite and carbides. The current study confirmed previous findings and contributed to existing knowledge that depending on the tempering temperature, the types of carbide formed during double tempering were M2C, Fe3C, M6C and M23C6 carbides. The present study findings add substantially to our understanding of the carbide formation sequence in the H21 tool steel during double tempering. No secondary peak hardening was observed, and the highest hardness (505 HV) was obtained after austenising at 1 250°C and double tempering at 650°C, which implies that the double tempering of the H21 tool steel should be carried out below 650°C.
AUSTENITE FORMATION OF STEEL3401 SUBJECTED TO RAPID COOLING PROCESS
2007
Hadfield's austenitic manganese steel is still commonly used for railroad components such as frogs and crossings and also for rock-handling materials. This material contains approximately 1.2% carbon and 12 to14% Mn. This paper presents the microstructural development of the austenitic manganese steel-3401 due to different heating regimes followed by rapid cooling process. The material is heated to 1050ºC followed by a rapid cooling process which caused the solid solution of the carbides to be precipitated in the grain of the pure austenite phase. The tempering temperature is set between 400ºC to 550ºC at 50º C interval. The microstructural examination of the samples showed that the formation of austenite begins by precipitation of iron and manganese carbides at the grain boundaries, progressively followed by the appearance of a new constituent which later extended to the interior of the grains. The new phase formation increased with increasing temperature, showing temperature dependence of formation.
2009
The subject of investigation was the steel of type 217H12WF/AISI D3. The main purpose of the studies was to establish effect of tempering temperature throughout 120 min on the changes of contents of carbides. The tempering was carried out for hardened steel samples after austenitizing in temperatures of 950, 1050, 1150 °C during 30 min. It was found that during tempering of hardened steel in the temperature range of 100-400 °C after austenitizing at 950 °C and 1050 °C the intensity of release/separation of carbides is small and it increases strongly with the temperature rise. In the hardened steel after austenitizing at 1150 °C the carbides begin to separate/release not before the tempering at about 400 °C and very intensively above 500 °C tempering. After tempering at 700 °C the contents of carbides in the steel is less than the contents of carbides in the annealed steel in the degree the more so as the higher has been the austenitizing temperature in the hardening operation. That ...
Mössbauer study of the effect of alloying elements on the carbide phase in cold-worked steel
Physica Status Solidi (a), 1979
The effect of the alloying elements on the cementite decomposition during the steel plastic deformation is studied b y means of the PU' GR technique. The decomposition is shown to be governed by the competition between the binding energy of the carbon atoms t o the dislocations in ferrite and the cementite solution heat. Among the elements under consideration vanadium and nickel suppress the cementite decomposition most effectively. The alloying elements distribution among the Gand S-sites of the cementite lattice is inhomogeneous. The G-sites are occupied predominantly by the elements that reduce the carbon chemical potential in the iron compounds (V, 1x0, Mn) and the S-sitesby those increasing it (Si). The plastic deformation changes the ratio of the alloying atoms populations of the Gand S-sites in the residual cementite. Mittels NGR-Technik wird der EinfluS der Legierungselemente auf die Cementit-Zersetzung wahrend der plastischen Deformation untersucht. Es wird gezeigt, daIJ die Zersetzung durch die Konkurrenz zwischen der Bindungsenergie der Kohlenstoffatome an Versetzungen im Ferrit und der Losungswarme des Cementit gesteuert wird. Unter den betrachteten Elementen unterdruckt Vanadium und Nickel die Cementitzersetzung a m wirkungsvollsten. Die Verteilung der legierenden Elemente zwischen den G-und S-Platzen des Cementitgitters ist inhomogen. Die G-Platze werden vorwiegend durch Elemente besetzt, die das chemische Potential von Kohlenstoff in Eisenverbindungen herabsetzen (V, Mo, Mn), und die S-Platze durch diejenigen, die es erhiihen (Si). Die plastische Verformung andert das Verhaltnis der Besetzung der Legierungsatome der Gund S-Platze im Restcementit.
Materials and Manufacturing Processes, 2007
The aim of this work was to investigate the effect of the carbides precipitated on the hardness and structure in the heat-affected zone of a Hadfield steel that has been used as broke stone tool during ten months and that have to be repaired by the welding process. The steel presents significant structural changes for the presence of the discontinuities in the heat-affected zone, that affect the hardness and the structure in comparison to the homogenized sample. The investigation is carried out with X-ray diffraction (XRD), microhardness Vickers, and Scanning Electron Microscopy (SEM) system. According to the XRD patters, the presence of Manganese carbides was identified. The identification of the types of carbides present in the steel structure allows us to say that it belongs to the Mn 23 C 6 and Mn 7 C 3 type.