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 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.

Structure and Property of Sub-Zero Processed Cold Work Die Steel

2013 ◽  
Author(s):  
Debdulal Das ◽  
Kalyan K. Ray ◽  
Apurba K. Dutta
Keyword(s):  
Mechanical Properties ◽  
Cryogenic Treatment ◽  
Cold Work ◽  
Cold Treatment ◽  
Homogeneous Distribution ◽  
Tool Steels ◽  
Deep Cryogenic Treatment ◽  
Structure And Property ◽  
Conventional Heat Treatment ◽  
Processing Cycle

This study examines the influence of different sub-zero processing routes on microstructure and mechanical properties of a cold work tool steel. Incorporation of controlled sub-zero processing cycle in between hardening and tempering treatment of tool steels increases the amount of ultrafine carbide particles with improved homogeneous distribution in addition to reduction in retained austenite content; these modifications are found to be enhanced with decreasing lowest temperature of the sub-zero processing cycle. It has been demonstrated that with reference to conventional heat treatment, sub-zero processing moderately improves hardness and marginally reduces fracture toughness but substantially enhances wear resistance of the selected steel; the extent of variations, in general, increase in the order of cold treatment, shallow cryogenic treatment and deep cryogenic treatment. The relationships of microstructural modifications with the variations of mechanical properties of tool steels due to different sub-zero processing have been established.

Effect of Deep Cryogenic Treatment on Carbide Precipitation and Mechanical Properties of Tool Steel

2006 ◽  
Vol 118 ◽  
pp. 9-14 ◽  
Author(s):  
Young Mok Rhyim ◽  
Sang Ho Han ◽  
Young Sang Na ◽  
Jong Hoon Lee
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Tool Steel ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Carbide Precipitation ◽  
Deep Cryogenic Treatment ◽  
Tempering Temperature ◽  
Fine Carbide ◽  
Forming Temperature

It is well known that the durability of tool steel could be improved by deep cryogenic treatment. It has been assumed that the increase of service life of tool steel caused by decrease of retained austenite and/or by formation of nano-scale fine η-carbide. But the principles of deep cryogenic treatment remain unclear yet. In this research, to manifest the effect of deep cryogenic treatment on wear resistance, the specimen was emerged in liquid nitrogen for 20 hours for deep cryogenic treatment after austenitizing and the following tempering temperature was varied. The microstructure of specimens was observed using TEM and the mechanical properties and wear resistance were examined. As the tempering temperature increased, the carbides became larger and fine carbides were formed above certain temperature. In the case of deep cryogenic treated specimen, the number of carbides increased while the carbides size was decreased, furthermore, the fine carbide forming temperature was lowered also. It was considered that the deep cryogenic treatment increased the driving force for the nucleation of carbides. As tempering temperature increased, hardness decreased while wear resistance and impact energy increased. The deep cryogenic treated specimens showed this tendency more clearly. It was considered that the wear resistance is affected not only to the hardness but also to the precipitation of fine carbides, and this carbide evolution can be optimized through the deep 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.

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.

Sintered High Carbon Steels: Effect of Thermomechanical Treatments on their Mechanical and Wear Performance

2008 ◽  
Vol 591-593 ◽  
pp. 271-276 ◽  
Author(s):  
M.A. Martinez ◽  
R. Calabrés ◽  
J. Abenojar ◽  
Francisco Velasco
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Thermomechanical Treatment ◽  
Bending Strength ◽  
Carbon Steels ◽  
Tool Steels ◽  
High Carbon ◽  
Wear Performance ◽  
Metallographic Study

In this work, ultrahigh carbon steels (UHCS) obtained by powder metallurgy with CIP and argon sintered at 1150°C. Then, they were rolled at 850 °C with a reduction of 40 %. Finally, steels were quenched at 850 and 1000 °C in oil. In each step, hardness, bending strength and wear performance were evaluated. Obtained results are justified with a metallographic study by SEM. Both mechanical properties and wear resistance are highly favoured with the thermomechanical treatment that removes the porosity of the material. Moreover, final quenching highly hardens the material. The obtained material could be used as matrix for tool steels.

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 Wear evaluation and microstructure analysis of cryogenically treated AISI 440C Bearing steel

2021 ◽  
Author(s):  
Idayan A ◽  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
Palanikumar K
Keyword(s):  
Wear Resistance ◽  
Cryogenic Treatment ◽  
Research Work ◽  
Bearing Steel ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Heat Treated ◽  
Increase Wear Resistance ◽  
Wear Evaluation

In this research work, two types of cryogenic treatment such as deep cryogenic treatment (-196oC) and shallow cryogenic treatment (-80oC) have been adopted for wear resistance to increase in AISI 440C bearing steel. This paper has been focused to increase Wear Resistance (WR) through deep micro structural analyses, and also attention has been made to correlate the microstructure with the wear character of Deep Cryogenic treated (DCT) specimens, Conventional Heat Treated (CHT) specimens and Shallow Cryogenic Treated (SCT) specimens. Micro structural examinations have been carried out in the specimens through Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX) and X-Ray Diffraction (XRD). Wear characteristics of AISI 440C bearing steel has been studied. The outcome of the research disclosed that the DCT specimens have higher wear resistance than SCT and CHT specimens. The effective wear mechanisms recognized were the constitution of white layers and delamination of white layers. The microstructures of the materials have been varied through heat treatment process. The modification of Secondary Carbides (SCs) precipitation characteristics and its reduction of retained austenite in the microstructure have been correlated with wear character and these are the liable mechanism to raise the wear resistance of bearing steels through DCT.

scholarly journals Microstructural evolution during austempering of a ASTM A-532 CLASS III type high chromium white cast iron undergoing abrasive wear

2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Oscar Fabián Higuera-Cobos ◽  
Jeison Bucurú-Vasco ◽  
Andrés Felipe Loaiza-Patiño ◽  
Mónica Johanna Monsalve-Arias ◽  
Dairo Hernán Mesa-Grajales
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Cast Iron ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Retained Austenite ◽  
White Cast Iron ◽  
Abrasive Wear Resistance ◽  
Class Iii ◽  
High Chromium

This paper studies the influence of variables such as holding temperatures and times during austempering of High Chromium White Cast Iron (HCWCI), with the following chemical composition: Cr 25 %, C 3 %, Si 0.47 %, Mn 0.74 % and Mo 1.02 %. The aim of the austempering was to modify the percentage of retained austenite and its correlation to abrasive wear resistance under different conditions.Microhardness tests, SEM-EDS and XRD were performed to determine mechanical properties, chemical composition, and type of carbides and microstructures present, respectively. The tests complied with the ASTM G-65 standard. Results showed that the best performance against abrasion was achieved for austempering at 450 ºC with holding time of 6 hours.

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