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Journal of Materials Science & Technology 2013年第1期29卷 82-88页

作者： Chaolei Zhang Leyu Zhou yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

Heredity in the microstructure and mechanical properties of hot-rolled spring steel wire 60Si2MnA during heat treatment process was investigated comprehensively. The steel was isothermally transformed to obtain various hot-rolled microstructure （pearlite fineness within the range of 140-510 nm） and mechanical properties, and followed by some quenching-tempering treatment. Afterwards, microstructure was characterized by optical microscopy, scanning electron microscopy and quantitative metallography, and mechanical properties were determined by tensile test. The results indicated that the hot-rolled microstructure with a coarsen pearlite structure had been changed after reheating, to a austenite microstructure with bigger and more uneven grain size, and finally to a coarsen tempered microstructure. And the average austenite grain size and standard deviation of its distribution in quenched microstructure were observed to depend linearly on the interlamellar spacing in hot-rolled microstructure. Besides, to obtain a good combination of the final strength and plasticity, an optimum value range （190-280 nm） of the interlamellar spacing had been determined for the interlamellar spacing in hot-rolled microstructure.

关键词： Spring steel Hot-rolling Heat treatment Microstructure Mechanical properties Heredity

Solid State Synthesis and Thermoelectric Properties of Mg-Si-Ge System

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Journal of Materials Science & Technology 2005年第5期21卷 618-622页

作者： Renbo SONG yazheng liu Tatsuhiko AIZAWA School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Center for Collaborative Research The University of Tokyo Komaba 4-6-1 Meguro-ku Tokyo 153-8904 Japan

Thermoelectric materials, Mg2Si1-xGex （x=0, 0.2, 0.4, 0.6, 0.8, 1）, have been prepared by bulk mechanical alloying （BMA） and hot pressing （HP）. The electrical conductivity, Seebeck coefficient and thermal conductivity were measured from room temperature up to about 700 K. The electrical conductivity of all the samples increases with increasing temperature, while the Seebeck coefficient and thermal conductivity decrease with increasing temperature. Mg2Si and Mg2Si0.8Ge0.2 possess negative type of conductivity, while for other compounds it is positive. At the same time, the effect of hot processing condition on thermoelectric properties was also investigated. The maximum figure of merit of Mg2Si0.6Ge0.4 was obtained with the processing parameter of BMA at 600 cycles and hot pressing at 773 K and i GPa for i h.

关键词： Solid-state synthesis Mg2Si1-xGex Bulk mechanical alloying Thermoelectric Hot pressing

Heat Treatment Properties of 42CrMo Steel for Bearing Ring of Varisized Shield Tunneling Machine

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 383-388页

作者： Bo Jiang Leyu Zhou Xinli Wen Chaolei Zhang yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

The heat treatment properties of 42CrMo steel for bearing ring of varisized shield tunneling machine were investigated by optical microscope （OM）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, and impact tests. The addition of 0.03 wt% C into 42CrMo steel can increase the hardness. But it reduces the impact energy by 46 J because of the appearance of coarser carbides in the matrix and the carbides along the austenite grain boundary. The addition of 0.40 wt% Mn into 42CrMo steel can improve hardenability. However, the toughness of steel is also reduced by 26 J mainly because of the coarsening of carbides and the strengthening of matrix. Both hardenability and toughness of 42CrMo steel can be improved by adding 1.49 wt% Ni and reducing 0.32 wt% Cr. The depth of hardening layer can be raised to 45 mm, and the impact energy at -20 ℃ is 120 J. Thus, it is concluded that a good combination of hardness, hardenability, and toughness of 42CrMo steel can be achieved by alloying with adding some content of C and Ni. Detailed content of C and Ni should be on the requirements of heat treatment properties of steel for bearing ring of varisized shield tunneling machine.

关键词： Shield tunneling machine Bearing ring 42CrMo steel Hardenability Toughness

Microstructure Control of Non-quenched and Tempered CT80Grade Coiled Tubing Steel

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 464-468页

作者： Leyu Zhou Bo Jiang Mingyang Li Fuchun Yuan Chaolei Zhang yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

Complex working condition of coiled tube （CT） steel demands high strength and low ratio of yield strength （YS） to tensile strength （TS）. Reasonable microstructure control is a key problem of CT steel. Controlled rolling and controlled cooling experiments were carded out by two kinds of tested steels with different chemical compositions to develop the non-quenched and tempered CT80 steel. Mechanical properties of the tested steels at different processes are all in good agreement with the properties requirement of CT80. Increasing of Mo and Nb contents improves transformation of acicular ferrite and martensite-austenite （M-A） islands. 4 vol% of fine M/A islands increase TS and decreases ratio of YS/ TS, Cooling rate increasing also improves acicular ferrite transformation and enhances TS, but has little effect on ratio of YS/TS. To meet the requirement of high strength and low ratio of YS/TS, optimized complex microstructure of the CT80 steel is composed of acicular ferrite, about 30 vol% of bainite and 4 vol% of M-A islands.

关键词： Coiled tube M-A islands Acicular ferrite Mechanical properties

绿色金融引导下的工业经济转型:可持续发展的路径

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现代工业经济和信息化 2024年第3期14卷 9-11页

作者：刘雅政路春艳哈尔滨商业大学黑龙江哈尔滨150028

在全球环境挑战和可持续发展需求日益增长的背景下,工业经济的传统模式面临着从高能耗、高污染向更环保、低碳模式的转变压力.绿色金融作为一种新兴的金融机制,对于推动这一转型至关重要,但同时也面临资金不足、政策不明确和市场机制不... 详细信息

在全球环境挑战和可持续发展需求日益增长的背景下,工业经济的传统模式面临着从高能耗、高污染向更环保、低碳模式的转变压力.绿色金融作为一种新兴的金融机制,对于推动这一转型至关重要,但同时也面临资金不足、政策不明确和市场机制不完善等挑战.基于此,深入分析了绿色金融在工业经济转型中的作用,探讨了其对技术创新的推动作用、与环境社会治理(ESG)的关联,以及绿色金融在实践中的应用案例,旨在为绿色金融的发展提供策略性建议,推动工业经济实现更加绿色和可持续的发展路径.

关键词：绿色金融工业经济转型技术创新环境社会治理可持续发展

Simulation of annealing process effect on texture evolution of deep-drawing sheet Stl5

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Journal of University of Science and Technology Beijing 2005年第6期12卷 512-516页

作者： Jinghong Sun yazheng liu Leyu Zhou Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

A two-dimensional cellular automaton method was used to simulate grain growth during the recrystallization annealing of deep-drawing sheet St 15, taking the simulated result of recrystallization and the experimental result of the annealing texture of deepdrawing sheet St15 as the initial condition and reference. By means of computer simulation, the microstructures and textures of different periods of grain growth were predicted. It is achieved that the grain size, shape and texture become stable after the grain growth at a constant temperature of 700℃ for 10 h, and the advantaged texture components { 111 } 〈 110 〉 and { 111 } 〈 112〉 are dominant.

关键词： cellular automaton deep-drawing sheet texture simulation

Computer simulation on the controlled cooling of 82B high-speed rod

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Journal of University of Science and Technology Beijing 2008年第3期15卷 330-334页

作者： Jinqiao Xu yazheng liu Shumei Zhou School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

A modified temperature-phase transformation field coupled nonlinear mathematical model was made and used in computer simulation on the controlled cooling of 82B high-speed rods. The surface temperature history and volume fraction of pearlite as well as the phase transformation history were simulated by using the finite element software Marc/Mentat. The simulated results were compared with the actual measurement and the agreement is good which can validate the presented computational models.

关键词： high-speed steel controlled cooling phase transformation computer simulation

汽车曲轴用非调质钢C38+N的热变形行为研究

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热加工工艺 2023年第24期52卷 52-58页

作者：孙鹤刘雅政中国中钢集团有限公司北京100080 北京科技大学材料科学与工程学院北京100083

以重型汽车曲轴用C38+N非调质钢为对象,对其热变形行为开展实验研究。对C38+N钢在850~1250℃保温不同时间时的奥氏体晶粒长大行为进行研究。得出模铸轧材和连铸轧材C38+N钢奥氏体晶粒长大激活能分别为7.49×10^(4)J/mol、7.87×10^(4)J/... 详细信息

以重型汽车曲轴用C38+N非调质钢为对象,对其热变形行为开展实验研究。对C38+N钢在850~1250℃保温不同时间时的奥氏体晶粒长大行为进行研究。得出模铸轧材和连铸轧材C38+N钢奥氏体晶粒长大激活能分别为7.49×10^(4)J/mol、7.87×10^(4)J/mol。计算并建立了不同实验状态下的奥氏体晶粒长大模型,分析了C38+N钢模铸轧材、连铸轧材奥氏体晶粒长大行为差异的原因是连铸轧材比模铸轧材的MnS分布更加弥散,MnS对奥氏体晶界有钉扎作用。

关键词：非调质钢热变形行为奥氏体晶粒

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集装箱用高强度耐候钢的开发及研究现状

材料导报 2022年第4期36卷 169-177页

作者：何国宁蒋波何博胡学文刘雅政北京科技大学材料科学与工程学院北京100083 北京科技大学新材料技术研究院北京100083 马鞍山钢铁股份有限公司技术中心安徽马鞍山243041

耐候钢在自然环境中与空气、雨水等发生反应,表面会形成稳定而致密的保护性锈层,相对于普碳钢,其具有较高的耐腐蚀性,因此,被大量应用于石油钻井、集装箱、铁道车辆等使用环境恶劣、对耐腐蚀性能有一定要求的结构中。近年来,在中欧班列... 详细信息

耐候钢在自然环境中与空气、雨水等发生反应,表面会形成稳定而致密的保护性锈层,相对于普碳钢,其具有较高的耐腐蚀性,因此,被大量应用于石油钻井、集装箱、铁道车辆等使用环境恶劣、对耐腐蚀性能有一定要求的结构中。近年来,在中欧班列、中亚班列等线路的快速发展以及“一带一路”倡议和高速治超等国家政策的支持导向下,铁路集装箱运输行业得到迅速发展,集装箱的轻量化、减薄化是其未来主要的发展方向。作为铁路集装箱主要材料的耐候钢,尤其是屈服强度为700 MPa级的高强耐候钢,由于其具有高的强度,可以大幅减轻集装箱的质量,实现集装箱的减薄,将得到大量应用。国外耐候钢开发起步较早,已经大规模推广应用,而我国的耐候钢虽然已经有所应用,但应用进展缓慢,仍需要开展高强度、高耐腐蚀性耐候钢的研发工作,以满足铁路集装箱的应用需求。目前,国内外学者对耐候钢的研究主要集中于不同成分体系下的耐腐蚀机理以及强韧化机理。本文从耐候钢的耐腐蚀机理、强韧化机理以及焊接性能方面进行了综述,主要针对钢的强韧性、焊接性以及耐候性等方面进行考虑,结合国内外耐候钢研究开发的经验,提出了高强度耐候钢化学成分设计思路和变形制度、温度制度和冷却制度的控制建议,确定了700 MPa以下级别高强耐候钢显微组织主要为铁素体+珠光体或粒状贝氏体;而700 MPa级别高强耐候钢显微组织控制目标则为细小的针状铁素体或粒状贝氏体。通过固溶强化、细晶强化、析出强化以及相变强化等多种手段满足性能要求,为今后集装箱用高强度耐候钢的研究和设计提供参考及依据。

关键词：耐候钢耐腐蚀性成分设计高强度焊接性

基于23MnNiMoCr54钢复杂显微组织和表面脱碳演变规律的退火条件控制

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材料导报 2022年第1期36卷 126-131页

作者：赵帆胡昊刘雅政张志豪谢建新北京科技大学新材料技术研究院北京100083 北京科技大学材料先进制备技术教育部重点实验室北京100083 北京科技大学材料科学与工程学院北京100083

轧材显微组织特征和表面脱碳是高强度矿用圆环链钢质量控制的关键,对矿用圆环链的编链、焊接、热处理、预拉伸工序乃至服役性能有着重要影响。本实验研究了退火温度和气氛对矿用高强度圆环链钢23MnNiMoCr54轧材硬度、显微组织和表面脱... 详细信息

轧材显微组织特征和表面脱碳是高强度矿用圆环链钢质量控制的关键,对矿用圆环链的编链、焊接、热处理、预拉伸工序乃至服役性能有着重要影响。本实验研究了退火温度和气氛对矿用高强度圆环链钢23MnNiMoCr54轧材硬度、显微组织和表面脱碳的影响。研究结果表明,在660~710℃退火后,退火前的马氏体、贝氏体分别转变为回火索氏体、退火态贝氏体,碳化物球化程度提高,轧材硬度较退火前显著降低,并且随退火温度升高,硬度也逐渐降低。在720~730℃退火后,出现由粗大马氏体、铁素体、少量碳化物组成的异常组织,轧材硬度较高。另一方面,随着退火温度由660℃升高至730℃,表面脱碳层深度逐渐增加;退火温度升高至700℃以后,表面脱碳层深度随温度升高增加较快。在710℃退火时,随着氧气体积浓度由21%降低至约0%,表面脱碳层深度逐渐减小;当氧气浓度降低至5.25%以下后,直边位置不再产生表面脱碳。23MnNiMoCr54轧材的退火温度应控制在680~700℃,为尽量减少表面脱碳,可考虑将退火炉内的氧气体积浓度控制在5%以下。

关键词：矿用圆环链钢退火硬度显微组织表面脱碳