scholarly journals Examination of Heat Treatment on the Microstructure and Wear of Tool Steels

2019 ◽  
Vol 2 (2) ◽  
pp. 87-92
Author(s):  
Enikő Réka Fábián ◽  
László Tóth ◽  
Csenge Huszák
Keyword(s):  
Wear Resistance ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Residual Austenite ◽  
Tool Steels ◽  
Austenite Content ◽  
The Matrix ◽  
Primary Carbides ◽  
Matrix Hardness ◽  
Multiple Tempering

Abstract The microstructure of the investigated X153CrMoV12 grade tool steel in delivered condition consisted of spheroidal matrix and primary carbides. The primary carbides were not dissolved under austenitisation time on either 1030°C or 1070°C. The microstructure and abrasion resistance of the steel changed due to quenching from different austenitisation temperatures. After conventional quenching from the higher austenitising temperature, there is more residual austenite in the steel than at quenching from the lower austenitisation temperature, which decreased the wear resistance. As a result of quenching from 1070°C followed by a multiple tempering process around 500 to 540°C, the retained austenite content is reduced and finely dispersed carbides are precipitated in the matrix, resulting in a higher matrix hardness and an increased wear resistance. After cryogenic treatment, the residual austenite content decreases compared to the conventional process, which leads to an increase in hardness and wear resistance.

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.

scholarly journals Influence of modes of thermal hardening and the subsequent cryogenic processing on structure and properties of steel 38Ni3CrMoV

2021 ◽  
Vol 98 (2) ◽  
pp. 14-22
Author(s):  
S.V. Bobyr ◽  
◽  
P.V. Krot ◽  
G.V. Levchenko ◽  
O.Ye. Baranovska ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Retained Austenite ◽  
Thermal Stresses ◽  
Cryogenic Treatment ◽  
Steel Structure ◽  
Residual Austenite ◽  
Machine Building ◽  
Isothermal Quenching ◽  
Complex Alloy ◽  
Alloy Steels

For the production of various machine-building products - rolling rolls, parts of power equipment, piercing mandrels - complex alloy steels containing chromium and a significant number of other deficient alloying elements (nickel, vanadium, molybdenum) type 38Ni3CrMoV are used. The paper presents the results of research on the influence of modes of hardening and subsequent cryogenic treatment on the parameters of the structure, hardness and wear resistance of this steel. Visible changes in the microstructure of thermally improved steel samples during cryogenic treatment were not found, which can be explained by the high thermodynamic stability of the sorbitol structure and the practical absence of residual austenite due to its decomposition during high tempering. It is shown that cryogenic treatment of thermally improved 38Ni3CrMoV steel contributes to an increase in the hardness, toughness and wear resistance this steel (~3.8 %). In this case, there is a slight increase in the parameter and magnitude of microstresses of the crystal lattice, an increase in the density of dislocations due to the removal of thermal stresses. To obtain a multiphase structure of 38Ni3CrMoV steel with retained austenite, isothermal quenching from the γ - α region has been proposed. The use of cryogenic treatment for the experimental mode of hardening of 38Ni3CrMoV steel samples promotes the transformation of retained austenite in the final structure of the samples into martensite with a significant increase in the microhardness of its structural components at the 22.3 %. The experimental hardening mode + cryogenic treatment provides a significant increase in the hardness and wear resistance of 38Ni3CrMoV steel at the 21.6 % while ensuring a certain level of its impact toughness (more than 4 J/cm2) and can be recommended for the implementation of the technology of differentiated hardening of large-sized products made of 38Ni3CrMoV steel. Keywords: steel, structure, hardness, wear resistance, isothermal hardening, cryogenic treatment.

scholarly journals Effect of Cryogenic Treatment on Microstructure, Mechanical Properties and Distortion of Carburized Gear Steels

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1940
Author(s):  
Yongming Yan ◽  
Ke Liu ◽  
Zixiang Luo ◽  
Maoqiu Wang ◽  
Xinming Wang
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Low Temperature ◽  
Wear Mechanisms ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Austenite Content ◽  
Cryogenic Process ◽  
Carburized Gear ◽  
Gear Steels

The effects of cryogenic treatment and low temperature tempering on the microstructure, mechanical properties and distortion of the 20Cr2Ni4A and 17Cr2Ni2MoVNb carburized gear steels were investigated. The results showed that the case hardness of the experimental steels was increased after the cryogenic treatment, due to the decrease of the retained austenite content and the precipitation of the tiny carbides. The wear resistance of the two steels after cryogenic treatment was improved, although the wear mechanisms were different for 17Cr2Ni2MoVNb and 20Cr2Ni4A steels. The distortion of the Navy C-ring specimens underwent shrinkage before expansion during the cryogenic process, and the distortion of 17Cr2Ni2MoVNb steel was smaller than that of 20Cr2Ni4A steel.

scholarly journals INFLUENCE OF DEEP CRYOGENIC TREATMENT AT ABRASIVE WEAR RESISTANCE IN ASTM 743 CA6NM

2013 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
A. F. Hernandez ◽  
C. R. M. Silva ◽  
J. A. Araujo ◽  
J. D. B. De Mello
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Lath Martensite ◽  
Wear Test ◽  
Abrasive Wear Resistance ◽  
Deep Cryogenic Treatment ◽  
Conventional Heat Treatment ◽  
The Matrix

The Deep Cryogenic Treatment (DCT) has been used for improvement of steel mechanical properties, basically the abrasive wear resistance. At this work the cryogenic treatment at -190oC for 20 hours was applied, after conventional heat treatment, to improve its abrasive wear resistance. The specimens, divided in two groups, had been austenitized for forty five minutes at 965oC and 1065oC, respectively, then quenched in oil at room temperature. Afterwards they were tempered at 565oC for 90 minutes, and then cooled in air. Subsequently some samples were treated cryogenically, and some of them were submitted to a new cycle of tempering at 565oC for 90 minutes. The performed experiment included: hardness brinell, Xraydifratometry, metallography and micro-abrasive wear test. Variations in the microstructure with an improvement in the abrasive wear coefficient were found. These variations are probably a positive effect of the DCT on the samples microstructure. The microstructure were transformed from blocks of parallel lath martensite to small parallel or almost parallel packages of fine needles forming austenite. Traces of previous or retained austenite were found delimiting the grains. It is presumed that micro-carbide homogeneously distributed in the matrix and in the grain´s contours of the retained austenite was formed.

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.

Comportement au revenu d'un acier du type Z80CDSV8.2.1.1 pour cylindres de laminoirs à chaud

1996 ◽  
Vol 84 ◽  
pp. 3-12
Author(s):  
H. Djebaïli
Keyword(s):  
Magnetic Measurements ◽  
Residual Austenite ◽  
Progressive Increase ◽  
Continuous Heating ◽  
Preliminary Treatment ◽  
Hardness Testing ◽  
Physical Methods ◽  
The Matrix ◽  
Primary Carbides ◽  
Hot Hardness

Transformations in Cr-Mo-Si steels with a specific addition of Vanadium have been characterized precisely as well as their effect on the hardness of the materials. A preliminary treatment in the austenitic field leads to a limited enrichment of the matrix as well as temperature is less than 1050°C : only M3C and M23C6 carbides may then be dissolved. On the contrary, the dissolution of M7C3 and MC carbides is observed over 1100°C but is only partial even after treatment at 1150°C. After quenching from three distinct temperatures (1050-1100 and 1150°C), the microstructure consists of martensite, residual austenite and primary carbides (mainly M7C3 and MC type) ; different tempering treatments have been performed (isochronal, isothermal or on continuous heating) using various physical methods (dilatometry, DTA and magnetic measurements, TEM observations and hot hardness testing). According to the maximum θR temperature reached, the following structural evolutions were observed :•ε carbide precipitates at θR < 250° C in the a’ matrix, then M3C carbide forms between 250 and 350°C which transforms in M7C3 carbide from 450 to 500°C. At the same time (300- 500°C) a secondary hardening occurs linked to the formation of very fine V4C3 carbides : a progressive increase in hot hardness is observed while holding isothermally at 300-450°C.•From 450 to 600°C, the residual austenite is destabilized owing to the precipitation of small carbides in α'/γ interfaces and may be transformed on cooling either in bainite or secondary martensite. On the other hand that impoverished austenite may be transformed in (α + carbides) between 600-700°C. Besides in the same temperature range, M6C and M23C6 may be formed at the expense of fine M7C3 carbides previously formed.

Tool Steels

2015 ◽  
pp. 621-645
Keyword(s):  
Wear Resistance ◽  
Phase Transformations ◽  
Retained Austenite ◽  
High Speed ◽  
Cold Work ◽  
Heat Treating ◽  
Alloy Design ◽  
Tool Steels ◽  
Evolution Of Microstructure ◽  
Alloying Principles

Tools steels are defined by their wear resistance, hardness, and durability which, in large part, is achieve by the presence of carbide-forming alloys such as chromium, molybdenum, tungsten, and vanadium. This chapter describes the alloying principles employed in various tool steels, including high-speed, water-hardening, shock-resistant, and hot and cold work tool steels. It discusses the influence of alloy design on the evolution of microstructure and properties during solidification, heat treating, and hardening operations. It also describes critical phase transformations and the effects of partitioning, precipitation, segregation, and retained austenite.

scholarly journals The Effect of Thickness on the Properties of Laser-Deposited NiBSi-WC Coating on a Cu-Cr-Zr Substrate

Photonics ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 127
Author(s):  
Yury Korobov ◽  
Yulia Khudorozhkova ◽  
Holger Hillig ◽  
Alexander Vopneruk ◽  
Aleksandr Kotelnikov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Matrix Material ◽  
Copper Substrate ◽  
Thin Layers ◽  
Laser Deposition ◽  
The Matrix ◽  
High Level ◽  
Primary Carbides ◽  
Matrix Powder ◽  
Wear Tests

Ni/60WC coatings on copper substrate were placed via laser deposition (LD). A structural study was conducted using electron microscopy and a microhardness evaluation. Two body abrasive wear tests were conducted with a pin-on-plate reciprocating technique. A tool steel X12MF GOST 5960 (C-Cr-Mo-V 1.6-12-0.5-0.2) with a hardness of 63 HRC was used as a counterpart. The following results were obtained: Precipitation of the secondary carbides takes place in the thicker layers. Their hardness is lower than that of the primary carbides in the deposition (2425 HV vs. 2757 HV) because they mix with the matrix material. In the thin layers, precipitation is restricted due to a higher cooling rate. For both LD coatings, the carbide’s hardness increases compared to the initial mono-tungsten carbide (WC)-containing powder (2756 HV vs. 2200 HV). Such a high level of microhardness reflects the combined influence of a low level of thermal destruction of carbides during laser deposition and the formation of a boride-strengthening phase from the matrix powder. The thicker layer showed a higher wear resistance; weight loss was 20% lower. The changes in the thickness of the laser deposited Ni-WC coating altered its structure and wear resistance.

Effect of Deep Cryogenic Process on the Microstructure and Hardness and Wear Resistance of High Carbon Tool Steel

2018 ◽  
Vol 934 ◽  
pp. 100-104
Author(s):  
Yuan Ching Lin ◽  
Ji Wei Gong
Keyword(s):  
Wear Resistance ◽  
Tool Steel ◽  
Cryogenic Treatment ◽  
Wear Test ◽  
High Carbon ◽  
Deep Cryogenic Treatment ◽  
Treatment Conditions ◽  
The Matrix ◽  
Cryogenic Process ◽  
The Moment

In this investigation, the effects of different heat treatment conditions on the mechanical properties of high carbon tool steel (SK2) were explored. Experimental results indicated that immediately doing deep cryogenic treatment can effectively reduce retained austenite after quenching. The moment of the holding time for the cryogenic treatment was extended can promote the fine carbides precipitated, and thus increased its hardness. The results of X-ray diffraction showed that the carbides in the matrix included Fe3C and Fe7C3.The wear test results demonstrated that the specimen with Q-T1hr-C24hr-T1hr treatment has the highest wear resistance than the others, which was caused by the effect of several tempering processes to improve toughness of the matrix and to precipitate considerable quantities of the fine carbides.

scholarly journals Wear Resistance of High C High Si Steel with Low Retained Austenite Content and Kinetically Activated Bainite

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 672 ◽  
Author(s):  
Bojan Podgornik ◽  
Mihael Brunčko ◽  
Peter Kirbiš
Keyword(s):  
Wear Resistance ◽  
Retained Austenite ◽  
Adhesive Wear ◽  
Cold Work ◽  
High Hardness ◽  
Bearing Steel ◽  
Austenite Content ◽  
Surrounding Matrix ◽  
Aisi D2 ◽  
Wear Mode

A novel high C high Si carbide free bainitic steel was developed for the production of cold work tools, knives, and rolls, requiring high hardness, toughness, as well as abrasive/adhesive wear resistance and resistance to galling at low costs. The steel was tribologically tested in dry sliding conditions under abrasive and adhesive wear mode, facilitated by using alumina and bearing steel ball as a counter-material, respectively. It was determined that carbide dissolution occurs under high contact pressures, thereby enriching the surrounding matrix with carbon and locally increasing the retained austenite content. The high retained austenite at the sliding interface increases the steels work hardening capacity and promotes superior wear resistance when compared to much more alloyed cold work tool steel, such as AISI D2. The steel has a high resistance to galling as determined by sliding against a soft steel bar due to its chemical composition.

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