The Effects of Quenching and Tempering Treatment on the Hardness and Microstructures of a Cold Work Steel

2019 ◽  
Vol 4 (1) ◽  
pp. 286-294
Author(s):  
László Tóth ◽  
Réka Fábián
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Cryogenic Treatment ◽  
Cold Work ◽  
Chromium Steel ◽  
Primary Carbide ◽  
Tempering Temperature ◽  
Tempering Treatment ◽  
Primary Carbides

The X153CrMoV12 ledeburitic chromium steel characteristically has high abrasive wear resistance, due to their high carbon and high chromium contents with a large volume of carbides in the microstructure. This steel quality has high compression strength, excellent deep hardenability and toughness properties, dimensional stability during heat treatment, high resistance to softening at elevated temperatures. The higher hardness of cryogenic treated samples in comparison with conventional quenched samples mean lower quantity of retained austenite as at samples quenched to room temperature and tempered in similar condition. In the microstructure of samples were observed that the primary carbide did not dissolve at 1070°C and their net structure have not been changed during to heat treatment. During to tempering at high temperature the primary carbides have become more and more rounded. After low tempering temperature in martensite were observed some small rounded carbides also, increasing the tempering temperature the quantity of finely dispersed carbides increased, which result higher hardness. The important issues in heat treatment of this steels are the reduction or elimination of retained austenite due to cryogenic treatment.

Effect of Heat Treatment Processing Parameters on the Microstructure and Properties of Low-Carbon Cr-Ni-Mo Carburizing Bearing Steels

2015 ◽  
Vol 817 ◽  
pp. 231-237 ◽  
Author(s):  
Nan Zhang ◽  
Mao Sheng Yang ◽  
Shi Qing Sun
Keyword(s):  
Heat Treatment ◽  
Impact Toughness ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Processing Parameters ◽  
Bearing Steel ◽  
Low Carbon ◽  
Quenching Temperature ◽  
Tempering Temperature ◽  
The Impact

The low-carbon Cr-Ni-Mo carburizing bearing steel was tested with different heat treatment processes. Quenching-tempering temperature and cryogenic treatment (-73°C) wasstudied respectively onthe mechanical properties and microstructure.Results show thatthe increase of quenching temperature causes the micron-sized Cr-rich carbide re-dissolution and smaller quantity of retained austenite, makingthe strength and hardness of the tested steel increase and the impact toughness decrease. The tempering temperaturerising causesthe reduction of micro-residual stresses and smallerdegree of lattice distortion andlower dislocation density, resulting in the decrease of strength and the increase of impact toughness. Cryogenic treatment contributes to the refinement of martensite lath and precipitation of nanosized carbide and lowest quantity of retained austenite, improving the strength and impact toughness of the steel.The good comprehensive mechanical propertieswith the hardness of HRC41.3, tensile strength of 1413MPa,yield strength of 1168MPa, and impact toughness of 162J/cm2 can be obtainedby optimizing the heat treatment process parameters.

Effects of Cryogenic Treatment on the Microstructure and Mechanical Properties of High-alloyed Tool Steels

2020 ◽  
Vol 75 (5) ◽  
pp. 73-93
Author(s):  
Alwin Schulz ◽  
Chengsong Cui ◽  
Matthias Steinbacher ◽  
Tuncer Ümit ◽  
Martin Wunde ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Homogeneous Distribution ◽  
Tool Steels ◽  
Positive Effects ◽  
Heat Treated ◽  
Primary Carbides ◽  
Complete Transformation

Abstract In this work, the influence of a cryogenic treatment on the microstructure, mechanical properties and wear resistance of the high-alloyed tool steels X38CrMoV5-3, X153CrMoV12 and ~X190CrVMo20-4 were investigated. Based on tempering curves of the steels, the heat treatment parameters were determined for the mechanical and wear specimens so that the conventionally heat-treated steels and the cryogenically treated steels featured similar hardness. The investigations showed that an almost complete transformation of retained austenite and a more homogeneous distribution of secondary carbides in the microstructure could be achieved by incorporating a cryogenic treatment. However, the cryogenic treatment does not show significantly positive effects on the investigated mechanical properties and wear resistance of the tool steels. The wear resistance of the samples was dominated by primary carbides. The cryogenic treatment would have a positive effect on large tool components with large wall thicknesses in terms of uniform and complete transformation of retained austenite throughout the entire components.

Microstructure Characterization of High Carbon Alloy from the Ni-Ta-Al-Co-Cr System / Charakterystyka Mikrostruktury Wysokowęglowego Stopu Z Układu Ni-Ta-Al-Co-Cr

2012 ◽  
Vol 57 (4) ◽  
pp. 937-941 ◽  
Author(s):  
P. Bała
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Elevated Temperatures ◽  
Chromium Content ◽  
Volume Fraction ◽  
High Carbon ◽  
Cr System ◽  
Primary Carbides ◽  
Cast Condition

In the present work results of investigations of the new high carbon alloy from the Ni-Ta-Al-Co-Cr system are presented. The alloy has been designed to have a good tribological properties at elevated temperatures. The chemical composition of this material was designed to obtain a matrix strengthening by the precipitation of γ’ phase (Ni3(Al,Ta)) and the primary carbides volume fraction above 25%. The primary carbides should remain stable in the microstructure, regardless of the heat treatment, in order to increase a wear resistance. The results of microstructure investigations in the as-cast condition are presented. The type of phases appearing in the microstructure was determined and their morphology described. The main microstructure components of the investigated Ni-based alloy with high carbon, cobalt and chromium content are: the γ phase, which constitutes a matrix, the γ’ phase, which occurs as fine globular precipitates and the primary Ta and Cr carbides (of MC and M7C3 type - respectively).

scholarly journals Thermal stability of retained austenite in bainitic steel: an  in situ study

2011 ◽  
Vol 467 (2135) ◽  
pp. 3141-3156 ◽  
Author(s):  
A. Saha Podder ◽  
I. Lonardelli ◽  
A. Molinari ◽  
H. K. D. H. Bhadeshia
Keyword(s):  
Martensitic Transformation ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Bainitic Ferrite ◽  
Ambient Conditions ◽  
Two Phase ◽  
Tempering Temperature ◽  
Thermal Stability Of ◽  
Lower Carbon

The tempering of two-phase mixtures of bainitic ferrite and carbon-enriched retained austenite has been investigated in an effort to separate the reactions that occur at elevated temperatures from any transformation during cooling to ambient conditions. It is demonstrated using synchrotron X-radiation measurements that the residue of austenite left at the tempering temperature partly decomposes by martensitic transformation when the sample is cooled. It is well established in the published literature that films of retained austenite are better able to resist stress or strain-induced martensitic transformation than any coarser particles of austenite. In contrast, the coarser austenite is more resistant to the precipitation of cementite during tempering than the film form because of its lower carbon concentration.

Microstructure of Tool Steel X37CrMoV5 after Cryogenic Treatment and its Effect on Wear Resistance

2015 ◽  
Vol 647 ◽  
pp. 23-37 ◽  
Author(s):  
Dagmar Jandová ◽  
Pavel Šuchmann ◽  
Jana Nižňanská
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Dendritic Segregation ◽  
Tempered Martensite ◽  
Deep Freezing ◽  
Conventional Heat Treatment ◽  
Pin On Disc ◽  
Vanadium Carbides ◽  
Cryogenic Heat Treatment

<p>A deep cryogenic heat treatment (DCT) was applied to X37CrMoV5 steel, which included soaking at -160°C for 12 and 30 hours followed by tempering at 180°C. Microstructures were compared with those after conventional heat treatment (HT). Microstructures with conspicuous dendritic segregation were observed in all specimens. After HT coarser and finer tempered martensite occurred in depleted and enriched areas of carbon and alloying elements respectively. Coarse molybdenum and vanadium carbides, fine secondary Fe2MoC carbides and retained austenite were identified after HT. Deep freezing resulted in microstructure refinement, transformation of retained austenite into twinned martensite, spinodal decomposition of martensite plates and precipitation of semicoherent h-carbide. The mechanism of h-carbide precipitation was discussed. Wear rate was measured using pin-on-disc test. The best results were obtained after DCT with cryosoaking for 12 hours.</p>

Acoustic Emission and Fracture Characteristics of AISI D2 Tool Steel Tempered at Different Temperatures

2010 ◽  
Author(s):  
M. Ahmadi Najafabadi ◽  
J. Teymuri Shandi
Keyword(s):  
Heat Treatment ◽  
Acoustic Emission ◽  
Tool Steel ◽  
Cold Work ◽  
Tempering Temperature ◽  
Average Value ◽  
Different Temperatures ◽  
Aisi D2 ◽  
Cold Work Tool Steel ◽  
Ae Signals

Acoustic emission (AE) has been known as an excellent technique to monitor crack propagation and fracture mechanism. For more domination on AE behavior of materials, comprehensive knowledge on effective parameters is necessary. Heat treatment as one of the important factors on AE characteristics of a material must be considered. This investigation is primarily aimed at studying the effect of tempering heat treatment on characteristics of acoustic emission signals monitored during tension tests of a cold-work tool steel. Single edge notched samples of AISI D2 cold-work tool steel were prepared. Then, respectively annealing, austenitizing and tempering were performed. Tempering was carried out at 5 different temperatures from 0 to 575 C. Finally, samples were loaded at tension and AE signals recorded synergistically. Analyzing of the characteristics of AE signals showed that: (a) In all tempering conditions, the AECC increases slowly at the beginning and rapidly at the point of crack growth, although at higher tempering temperatures we have gradual rise in AECC plot; (b) Increasing tempering temperature, average value of AE count number, amplitude, energy and peak frequency decreases; (c) At 525 C, because of secondary hardening, average value of investigated AE parameters increase strongly and (d) analyzing the relation between fracture mode, AE characteristics and tempering temperature showed that special AE behavior of specimens tempered at 525 C is because of the transformation of retained austenite in ferritic matrix.

scholarly journals Optimization of Quenching and Tempering Parameters for the Precipitation of M7C3 and MC Secondary Carbides and the Removal of the Austenite Retained in Vanadis 10 Tool Steel

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 627 ◽  
Author(s):  
Alejandro Gonzalez-Pociño ◽  
Florentino Alvarez-Antolin ◽  
Juan Asensio-Lozano
Keyword(s):  
Heat Treatment ◽  
Tool Steel ◽  
Retained Austenite ◽  
Process Variables ◽  
Tempering Temperature ◽  
X Ray ◽  
Secondary Carbides ◽  
Service Behavior ◽  
Hardness Values ◽  
Quenching And Tempering

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. The highest hardness values were obtained when the tempering temperature was lower (500 °C). Tempering in air or oil did not have a significant influence on the hardness of the steel after double or triple tempering at 500 or 600 °C. These results allow the manufacturers of industrial tools and components that use this type of steel in the annealed state as a material to define the most suitable quenching and tempering heat treatment to optimize the in-service behavior of these steels.

scholarly journals Multiscale Analysis of the Microstructure and Stress Evolution in Cold Work Die Steel during Deep Cryogenic Treatment

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2122 ◽  
Author(s):  
Junwan Li ◽  
Xin Cai ◽  
Yiwen Wang ◽  
Xiaochun Wu
Keyword(s):  
Phase Transformation ◽  
Driving Force ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Cold Work ◽  
Multiscale Model ◽  
Stress Evolution ◽  
Deep Cryogenic Treatment ◽  
Mechanical Coupling ◽  
Transformation Stress

Through a combination of 3D representative volume element (RVE) and the metallo-thermo-mechanical coupling finite element (FE) analysis, a multiscale model was established to explore the localized characteristics of microstructure and stress evolution during deep cryogenic treatment (DCT). The results suggest that after cooling to near −160 °C, the largest intensity of martensite is formed, but the retained austenite cannot be eliminated completely until the end of DCT. The driving force for the precipitation of fine and uniform carbides during DCT is provided by the competition between the thermal and phase transformation stresses. Compared with the thermal stress, the phase transformation stress during DCT plays a more significant role. At the interface between retained austenite and martensite, a reduction of around 15.5% retained austenite even induces an obvious increase in the phase transformation stress about 1100 MPa. During DCT, the maximum effective stress in RVE even exceeds 1000 MPa, which may provide a required driving force for the precipitation of fine and homogeneously distributed carbide particles during DCT.

Heat Treatment and Mechanical Testing of AISI H11 Steel

2015 ◽  
Vol 656-657 ◽  
pp. 434-439 ◽  
Author(s):  
Sayyad Zahid Qamar
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
High Speed ◽  
Cold Work ◽  
Microstructural Analysis ◽  
Treatment Strategies ◽  
Dimensional Accuracy ◽  
Impact Testing ◽  
Air Cooling ◽  
Tempering Temperature

Belonging to the class of chromium tool steels, AISI H11 possesses very good toughness and hardness, and is therefore suitable for hot metalforming jobs performed at very high loads. Mostly used in fabrication of helicopter rotor blades, H11 also has great potential as a die steel in hot-work forging and extrusion. This alloy steel can be heat treated to increase the service life and dimensional accuracy of the die and tooling. Main aim of the current investigation was to formulate an optimum heat treatment strategy for H11 steel, especially for hot work applications. High-speed milling and electric discharge machining were used to fabricate samples for tensile and impact testing. After various types of heat treatment (annealing, austenitizing, air cooling or oil quenching, single and double tempering), these samples were tested for hardness, toughness (impact), yield strength, tensile strength, and ductility. Microstructural analysis was also performed to analyze the effect of heat treatment on mechanical properties. As tempering temperature increases, hardness initially increases and then starts to gradually decrease; impact strength first decreases and then increases; and yield strength exhibits a fluctuating pattern of initial decline followed by an increase and another decrease. Even though H11 steel is highly suitable for both hot and cold-work, it is surprisingly not a common choice for metalworking dies and tools. Results presented here can encourage die designers and hot-work practitioners to explore the versatility of this tool steel, and to adopt appropriate heat treatment strategies for different applications.

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