Effect of Cryogenic Treatment on the Microstructure Modification of SKH51 Steel

2021 ◽  
Author(s):  
Kaweewat Worasaen ◽  
Piyada Suwanpinij ◽  
Karuna Tuchinda
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Cryogenic Treatment ◽  
Constant Load ◽  
Holding Time ◽  
Primary Carbide ◽  
Deep Cryogenic Treatment ◽  
Microstructure Modification ◽  
Conventional Heat Treatment ◽  
The Matrix

This research aimed to investigate the microstructure modification mechanism used to improve the hardness and wear resistance of SKH51 steel. The cryogenic treatment (CT), including both shallow cryogenic treatment (SCT) and deep cryogenic treatment (DCT), was used to modify the microstructure of SKH51 steel in this research. The effect of short and long holding time (12 and 36 h) in CT was studied. The microstructures were evaluated by using a light optical microscopy (LOM) and a scanning electron microscopy (SEM). The phase identifications of the matrix, carbides, and a-parameter of the matrix were analyzed by using X-ray diffraction (XRD). The M6C and MC carbides size, aspect ratio, and distribution were analyzed using digimizer image analysis software on the SEM micrographs. Micro-Vickers were employed to evaluate the hardness of the targeted samples. Wear tests were performed by using a 6 mm diameter WC ball as the indenter and 5-N-constant load with a ball-on-disk wear tester. The results suggested that the increase of the secondary carbide was caused by the contraction and expansion phenomena of the matrix’s lattice, forcing the carbon atom out and acting as the carbide nucleation. The influence of holding time in the SCT and DCT regions was different. For the SCT, increasing the holding time increased the volume’s fraction of MC carbide. Conversely, the M6C carbide size grew with increasing holding time in the DCT region, while no significant increase in the number of MC carbide was observed. The cryogenic treatment was found to increase the volume fraction of the MC carbide by up to 10% compared to the conventional heat treatment (CHT) condition in the SCT region (both 12 and 36 h) and DCT with 12 h holding time. Due to the microstructure modification, it was found that the cryogenic treatment can improve material hardness and lead to an increase in the wear resistance of SKH51 by up to 70% compared to the CHT treated material. This was due to the increase in the compressive residual stress, precipitation of the MC, and growth of the M6C primary carbide.

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.

scholarly journals Effect of Cryogenic Treatment on Microstructure and Wear Resistance of Carburized 20CrNi2MoV Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 808 ◽  
Author(s):  
Binzhou Li ◽  
Changsheng Li ◽  
Yu Wang ◽  
Xin Jin
Keyword(s):  
Electron Microscopy ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Cryogenic Treatment ◽  
Wear Test ◽  
Deep Cryogenic Treatment ◽  
Transmission Electron ◽  
Conventional Heat Treatment ◽  
Carburizing Process ◽  
Ball On Disc

This paper investigated the response of carburized 20CrNi2MoV steel to cryogenic treatment including microstructure and wear resistance. Two cryogenic treatment methods including cryogenic treatment at −80 °C (CT) and deep cryogenic treatment at −196 °C (DCT) as well as conventional heat treatment (CHT) were carried out after carburizing process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD) were employed for microstructure characterization. The wear resistance was investigated by ball-on-disc sliding wear test on a multi-functional tribometer. The results show that the wear resistance of the experimental steel has been improved by 17% due to CT and by 25.5% due to DCT when compared to CHT. This significant improvement in wear resistance after cryogenic treatment is attributed to the microstructural changes including the finer martensitic structure, the reduction of retained austenite and the development of fine and more numerous carbides. Among these factors, the precipitation of fine carbides plays a more prominent role in enhancing 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 Comparison of Structure and Properties of Mo2FeB2-Based Cermets Prepared by Welding Metallurgy and Vacuum Sintering

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Hu Xu ◽  
Junsheng Sun ◽  
Jun Jin ◽  
Jijun Song ◽  
Chi Wang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Volume Fraction ◽  
Phase Evolution ◽  
304 Stainless Steel ◽  
Vacuum Sintering ◽  
Cored Wire ◽  
Welding Metallurgy ◽  
Metallurgical Bonding ◽  
The Matrix

At present, most Mo2FeB2-based cermets are prepared by vacuum sintering. However, vacuum sintering is only suitable for ordinary cylinder and cuboid workpieces, and it is difficult to apply to large curved surface and large size workpieces. Therefore, in order to improve the flexibility of preparing Mo2FeB2 cermet, a flux cored wire with 70% filling rate, 304 stainless steel, 60 wt% Mo powder and 40 wt% FeB powder was prepared. Mo2FeB2 cermet was prepared by an arc cladding welding metallurgy method with flux cored wire. In this paper, the microstructure, phase evolution, hardness, wear resistance and corrosion resistance of Mo2FeB2 cermets prepared by the vacuum sintering (VM-Mo2FeB2) and arc cladding welding metallurgy method (WM-Mo2FeB2) were systematically studied. The results show that VM-Mo2FeB2 is composed of Mo2FeB2 and γ-CrFeNi.WM-Mo2FeB2 is composed of Mo2FeB2, NiCrFe, MoCrFe and Cr2B3. The volume fraction of hard phase in WM-Mo2FeB2 is lower than that of VM-Mo2FeB2, and its hardness and corrosion resistance are also slightly lower than that of VM-Mo2FeB2, but there are obvious pores in the microstructure of VM-Mo2FeB2, which affects its properties. The results show that WM-Mo2FeB2 has good diffusion and metallurgical bonding with the matrix and has no obvious pores. The microstructure is compact and the wear resistance is better than that of VM-Mo2FeB2.

Evaluation of Deep Criogenic Treatment at Microabrasive Wear of Aisi D2 Steel

2015 ◽  
Vol 1120-1121 ◽  
pp. 1257-1263
Author(s):  
Cosme Roberto Moreira Silva ◽  
Tiago F.O. Melo ◽  
José A. Araújo ◽  
J.L.A. Ferreira ◽  
S.J. Gobbi
Keyword(s):  
Wear Resistance ◽  
Treatment Cycle ◽  
Cryogenic Treatment ◽  
Deep Cryogenic Treatment ◽  
Abrasive Resistance ◽  
Austenitization Temperature ◽  
Aisi D2 Steel ◽  
X Ray ◽  
Aisi D2 ◽  
D2 Steel

Wear resistance of tool steels can be increased with deep cryogenic treatment (DCT) application. Mechanisms related to DCT are still not completely understood. Microabrasive wear resistance of cryogenically treated samples of AISI D2 steel was evaluated in terms of austenitization temperature at heat treatment cycle and quenching steps related to DCT. X-ray difractometry, scanning and optical microscopy and quantitative evaluation of carbides with image analysis were carried out aiming material characterization. For samples subjected to higher austenitization temperatures, the DCT treatment does not increase abrasive wear resistance. For samples treated at lower austenitization temperature, the DCT treatment results on 44% increase at abrasive resistance. This effect is correlated to the increase of the amount of fine carbides distributed at samples matrices cryogenically treated.

Performance of a Matrix Type High Speed Steel after Deep Cryogenic and Low Tempering Temperature

2021 ◽  
Vol 1016 ◽  
pp. 1423-1429
Author(s):  
Kaweewat Worasaen ◽  
Andreas Stark ◽  
Karuna Tuchinda ◽  
Piyada Suwanpinij
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Cryogenic Treatment ◽  
High Speed Steel ◽  
High Energy ◽  
Single Step ◽  
Deep Cryogenic Treatment ◽  
Tempering Temperature ◽  
Matrix Type ◽  
Bcc Structure

A matrix type high speed steel YXR3 designed for a combination of wear resistance and toughness is investigated for its mechanical properties after hardening by deep cryogenic treatment follow by tempering. The deep cryogenic quenching carried out at -200 °C for 36 hours and the single step tempering results in an obvious improvement in wear resistance while balancing the toughness, comparing with the conventional quenching followed by a double tempering treatment. The quantitative image analysis reveals little difference in the MC carbide size distribution between tempering at different temperatures. The synchrotron high energy XRD confirms the MC type carbide with some evolution in its orientation together with tempered martensite approaching the BCC structure at higher temperatures. In contrary to the conventional quenching and tempering, the lowest tempering temperature at 200 °C yields a moderate drop in hardness with increase in surface toughness proportionally while exhibiting exceptional wear resistance. Such thermal cycle can be recommended for the industry both for the practicality and improved tool life.

Improving scratch-resistance and wear-resistance of VN film by deep cryogenic treatment with liquid nitrogen

2019 ◽  
Vol 36 (2) ◽  
pp. 206-215 ◽  
Author(s):  
Zhaobing Cai ◽  
Ran Chen ◽  
Jianguo Qian ◽  
Shujing Zheng ◽  
Shengyu Chen ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Liquid Nitrogen ◽  
Cryogenic Treatment ◽  
Scratch Resistance ◽  
Deep Cryogenic Treatment

scholarly journals Role of titanium carbide and alumina on the friction increment for Cu-based metallic brake pads under different initial braking speeds

Friction ◽  
2020 ◽  
Author(s):  
Tao Peng ◽  
Qingzhi Yan ◽  
Xiaolu Zhang ◽  
Yan Zhuang
Keyword(s):  
Wear Resistance ◽  
Titanium Carbide ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Interface Bonding ◽  
Brake Pads ◽  
Reinforced Composite ◽  
The Poor ◽  
The Matrix

AbstractTo understand the effect of abrasives on increasing friction in Cu-based metallic pads under different braking speeds, pad materials with two typical abrasives, titanium carbide (TiC) and alumina (Al2O3), were produced and tested using a scale dynamometer under various initial braking speeds (IBS). The results showed that at IBS lower than 250 km/h, both TiC and Al2O3 particles acted as hard points and exhibited similar friction-increasing behavior, where the increase in friction was not only enhanced as IBS increased, but also enhanced by increasing the volume fraction of the abrasives. However, at higher IBS, the friction increase was limited by the bonding behavior between the matrix and abrasives. Under these conditions, the composite containing TiC showed a better friction-increasing effect and wear resistance than the composite containing Al2O3 because of its superior particle-matrix bonding and coefficient of thermal expansion (CTE) compatibility. Because of the poor interface bonding between the matrix and Al2O3, a transition phenomenon exists in the Al2O3-reinforced composite, in which the friction-increasing effect diminished when IBS exceeded a certain value.

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