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Experimental study of cryogenic treatment of Karaganda coal samples

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PETROLEUM RESEARCH 2024年第3期9卷 359-368页

作者： Wang, Lei Yan, Xinchuang Sarmalayev, Iliyas Cha, Minsu Zhang, Dichuan Hazlett, Randy D. Chengdu Univ Technol Coll Energy State Key Lab Oil & Gas Reservoir Geol & Exploitat Chengdu 610059 Peoples R China Xian Shiyou Univ Engn Res Ctr Dev & Management Low Ultralow Permeab Minist Educ Xian 710065 Peoples R China Nazarbayev Univ Petr Engn Dept Astana 010000 Kazakhstan Jeju Natl Univ Dept Civil Engn Jeju 62343 South Korea Nazarbayev Univ Dept Civil & Environm Engn Astana 010000 Kazakhstan

Karaganda Coal Basin bears the largest undeveloped reserve of coalbed methane (CBM) in Kazakhstan, which lacks water resources for implementing large-volume hydraulic fracturing. cryogenic fracturing utilizing liquid nitrogen (LN2) has been trialled in fields and is a waterless fracturing technique under intensive research these days. This study aimed to evaluate the cryogenic treatment efficacy of Karaganda coal samples as well as to understand the coal permeability evolution during the thawing period. X-ray fluorescent spectrometry (XRF) and microscope imaging identified the compositional and structural heterogeneities of coal specimens mined from different interlayers. Acoustic emission test, permeability measurement, and microscope imaging comparatively characterized the dry coal structure alteration before and after immersion into LN2. cryogenic treatment slowed down the S-wave velocity through coal specimens, enhanced permeability by over 65 % after temperature recovery as well as created new fractures, enlarged existing ones, and spalled coal particles. Dynamic permeability evolution against temperature rise during the thawing process has been successfully captured for the first time. Overall, the experimental measurements support that the LN2 cryogenic fracturing technique would be effective in stimulating coalbeds for CBM production in Karaganda Coal Basin. (c) 2024 The Authors. Publishing services provided by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY license .

关键词： cryogenic treatment Karaganda coal Dynamic permeability Acoustic emission Microscopic image XRF composition LIQUID-NITROGEN

cryogenic treatment induced hardening for Cu-Zr-Ag-Al bulk metallic glasses

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Science China Technological Sciences 2013年第3期56卷 637-641页

作者： CHEN ZhenHua ZHANG LiKe LIU JiZi CHEN Ding College of Materials Science and Engineering Hunan University

Little is known about the mechanical properties of bulk metallic glassy alloys(BMGs) after cryogenic *** this study,the effects of cryogenic treatment(CT) on the microstructural transition and the mechanical properties of Cu-based bulk metallic glass(BMG) were *** results showed that submicron AlCu2Zr and Cu5Zr phases can precipitate from the Cu-Zr-Ag-Al matrix after 192 h *** formation of these nanometer-sized crystalline phases substantially enhanced the mechanical properties of the bulk amorphous *** micro-hardness and the compressive strength were found to increase respectively from 501 HV and 1510 MPa to 595 HV and 1910 MPa after cryogenic *** is a promising approach to strengthening metal glasses.

关键词： bulk glassy alloy cryogenic treatment strengthening crystallization

Effect of deep cryogenic treatment on the properties of 80CrMo12 5 tool steel

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International Journal of Minerals,Metallurgy and Materials 2012年第1期19卷 30-37页

作者： Kamran Amini Said Nategh Ali Shafyei Ahmad Rezaeian Department of Materials Engineering Majlesi Branch Islamic Azad University Department of Materials Engineering Science and Research Branch Islamic Azad University Department of Materials Engineering Isfahan University of Technology

The effect of deep cryogenic treatment on the mechanical properties of 80CrMo 12 5 tool steel was investigated. Moreover, the effects of stabilization （holding at room temperature for some periods before deep cryogenic treatment） and tempering before deep cryogenic treatment were studied. The results show that deep cryogenic treatment can eliminate the retained austenite, making a better carbide distribu- tion and a higher carbide amount. As a result, a remarkable improvement in wear resistance of cryogenically treated specimens is observed. Moreover, the ultimate tensile strength increases, and the toughness of the sample decreases. It is also found that both stabilization and tem- pering before deep cryogenic treatment decrease the wear resistance, hardness, and carbides homogeneity compared to the deep cryogeni- cally treated samples. It is concluded that deep cryogenic treatment should be performed without any delay on samples after quenching to reach the highest wear resistance and hardness.

关键词： tool steel cryogenic treatment stabilization wear resistance tensile strength hardness carbides

Influence of cryogenic treatment on the wear characteristics of 100Cr6 bearing steel

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 46-51页

作者： R.Sri Siva D.Mohan Lal P.Kesavan Nair M.Arockia Jaswin Department of Mechanical Engineering College of Engineering GuindyAnna University Department of Metallurgical and Material Engineering Indian Institute of Technology Madras Department of Mechanical Engineering Aksheyaa College of Engineering

A series of reciprocating wear tests were performed on the deep cryogenically treated and conventionally heat-treated samples of 100Cr6 bearing steel to study the wear resistance. The worn surfaces as well as the wear debris were analyzed by scanning electron microscopy. The improvement in wear resistance of the deep cryogenically treated samples ranges from 49% to 52%. This significant improvement in wear resistance can be attributed to finer carbide precipitation in the tempered martensitie matrix and the transformation of retained aus- tenite into martensite. X-ray diffraction analysis shows that the volume fraction of retained austenite in the conventionally heat-treated samples is 14% and that of the deep cryogenically treated samples is only 3%.

关键词： bearing steel cryogenic treatment wear resistance carbides martensite

Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment

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Journal of Iron and Steel Research International 2021年第3期28卷 360-369页

作者： Chang-sheng Li Bin-zhou Li Xin Jin Yu Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina Ansteel Group Ansteel Beijing Research InstituteBeijing102211China

Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment were *** treatment sample was quenched and tempered at 180℃ for 2 *** treatment samples were quenched,cryogenically treated at−80 and−196℃ for 4 h,slowly returned to room temperature and thereafter tempered at 180℃ for 2 h,and finally tempered at 180℃ for 2 *** scanning electron microscope,electron backscattering diffraction,X-ray diffraction and transmission electron microscope were adopted for microstructure *** results show that cryogenic treatment increases the fraction of high-angle grain boundaries and the precipitation of finely dispersed carbides in the matrix,decreases the volume fraction of inter-lath retained austenite,and hence improves the strength and *** with the conventional treatment,the hardness,yield strength and ultimate tensile strength of the steel after cryogenic treatment are increased by 11.7%,12.6%and 18.3%,respectively,while the impact energy is decreased by 9.8%.

关键词： Bearing steel cryogenic treatment Lath martensite Retained austenite Mechanical property

Effect of deep cryogenic treatment on the formation of nano-sized carbides and the wear behavior of D2 tool steel

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 795-799页

作者： Kamran Amini Amin Akhbarizadeh Sirus Javadpour Department of Materials Science and Engineering Majlesi Branch Islamic Azad University Isfahan 86315/111 Iran Department of Materials Science and Engineering School of Engineering Shiraz University Zand Ave. Shiraz *** Fars Iran

The effect of deep cryogenic treatment on the microstructure, hardness, and wear behavior of D2 tool steel was studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD）, hardness test, pin-on-disk wear test, and the reciprocating pin-on-fiat wear test. The results show that deep cryogenic treatment eliminates retained austenite, makes a better carbide distribution, and increases the carbide content. Furthermore, some new nano-sized carbides form during the deep cryogenic treatment, thereby increasing the hardness and improving the wear behavior of the samples.

关键词： cryogenic treatment tool steel nano-sized carbides wear resistance hardness austenite

Effects of cryogenic treatment on the thermal physical properties of Cu_(76.12) Al_(23.88) alloy

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Rare Metals 2011年第6期30卷 644-649页

作者： WANG Ping LU Wei WANG Yuehui LIU Jianhua ZHANG Ruijun State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China College of Civil Engineering andMechanics Yanshan University Qinhuangdao 066004 China Tangshan Vocational Technology College Tangshan 063000 China College of Physics ＆ Chemistry Hebei Normal University of Science ＆ Technology Qinhuangdao 066004 China

The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu76.12Al23.88 alloy before and after cryogenic treatment in the heating temperature range of 25℃ to 600℃ were measured by thermal constant tester and thermal expansion instrument. The effects of cryogenic treatment on the thermal physical properties of CU76,12A123,88 alloy were investigated by comparing the variation of the thermal parameters before and after cryogenic treatment. The results show that the variation trend of the thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of CU76.12Al23.88 alloy after cryogenic treatment was the same as before. The cryogenic treatment can increase the thermal diffusion coefficient, thermal conductivity, and thermal expansion coeffi- cient of Cu76.12Al23.88 alloy and decrease its heat capacity. The maximum difference in the thermal diffusion coefficient between the before and after cryogenic treatment appeared at 400℃. Similarly, thermal conductivity was observed at 200℃.

关键词： Cu76.12Al23,88 alloy cryogenic treatment thermal diffusion coefficient thermal expansion coefficient

Effect of cryogenic treatment on Property of 14Cr2Mn2V High Chromium Cast Iron Subjected to Subcritical treatment

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Journal of Iron and Steel Research International 2006年第6期13卷 43-48页

作者： LIU Hao-huai WANG Jun YANG Hong-shan SHEN Bao-luo GAO She-ji HUANG Si-jiu Metal Material Department Siehuan University Chengdu 610064 Sichuan China Department ofMechanical Measurement National Institute of Measurement and Testing Technology Chengdu 610021Siehuan China Sijiu Rare Earth Alloy Foundry Chengdu 610211 Siehuan China

Effect of cryogenic treatment on the microstructure, hardening behavior and abrasion resistance of 14Cr2Mn2V high chromium cast iron （HCCI） subjected to subcritical treatment was investigated. The results show that cryogenic treatment after subcritical treatment can obviously improve the hardness and abrasion resistance of HCCI because abundant retained austenite is transformed into martensite and fine secondary carbides E（Fe, Cr）23 C6 ] precipitate. The amount of martensite and precipitated secondary carbide in HCCI experiencing subcritical treatment followed by cryogenic treatment was more than that experiencing the subcritical treatment followed by air cooling. When the abrasion resistance of HCCI reaches the maximum, its microstructure contains about 15 % retained austenite. cryogenic treatment can further reduce the austenite content but the retained austenite cannot be transformed in to martensite completely.

关键词： high chromium cast iron cryogenic treatment subcritical treatment martensite transformation abrasion resistance

Influence of Shallow and Deep cryogenic treatment on Tribological Behavior of En 19 Steel

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Journal of Iron and Steel Research International 2011年第9期18卷 53-59页

作者： D Senthilkumar I Rajendran Department of Mechanical Engineering Dr Mahalingam College of Engineering and Technology

The influence of cryogenic treatment on the wear resistance of En 19 steel was studied. Furthermore, a comparative analysis on the effect of Deep cryogenic treatment （DCT, 196℃× 24 h）, Shallow cryogenic treatment （SCT -80℃ × 5 h） and Conventional Heat treatment （CHT） was done through dry sliding wear testing. The microstructures of CHT, SCT and DCT samples were also examined through scanning electron microscopy. The results indicated that the wear resistance of shallow and deep cryogenically treated samples is higher when compared to that of conventionally treated samples. X-ray diffraction pattern revealed that the transformation of retained austenite into martensite is responsible for the wear resistance improvement.

关键词： steel wear cryogenic treatment automotive