检索结果-内蒙古大学图书馆

Effect of Central multiphase microstructure of Thick Plates on Work Hardening and Crack Propagation

Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 325-338页

作者： Lei Hu Liqin Zhang Feng Hu Kuan Zheng Guohong Zhang Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan430081China Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081China Analysis and Testing Center Wuhan University of Science and TechnologyWuhan430081China

The effect of multiphase microstructure in the center segregation zones(CSZ)of high-strength steel thick plates on work hardening characteristics and crack initiation/propagation were *** was correlated with deformation damage behavior by using Taylor factor(TF)gradients,kernel average misorientation(KAM),and geometric necessary dislocation(GND)*** results show that the segregation leads to a mixed structure of ferrite(soft phase)and martensite/bainite(hard phase)in the center of the thick *** to the 1/4 thickness(1/4 T)region,grain refinement occurred in the CSZ,with KAM values increasing from 0.24 to 0.49 and a decrease in the proportion of high-angle grain boundaries(>15°)from 77.4 to 51.8%.In the process of deformation,due to the influence of grain refinement and adjacent martensite/bainite,ferrite grains were divided into structural units with different TF *** higher KAM value and GND density at the interface between soft/hard phases resulted in severe work *** addition,the presence of micron-sized inclusions in the CSZ caused local strain concentration and non-continuous deformation of the matrix,which induced crack *** fracture surface showed a mixed mode of brittle cleavage fracture and ductile fracture.

关键词： Thick plate Center segregation zone multiphase microstructure Taylor factor Crack propagation

来源：评论

学校读者我要写书评

暂无评论

Viscoelasticity stage evolution characteristics and multiphase microstructure of aged crumb rubber-modified asphalt

引用

CONSTRUCTION AND BUILDING MATERIALS 2025年 469卷

作者： Chen, Ruipu Chen, Long Hu, Peng Zhu, Hongzhou Ou, Li Shandong Jiaotong Univ Sch Civil Engn Jinan 250357 Peoples R China Chongqing Jiaotong Univ Natl & Local Joint Engn Res Ctr Transportat & Civi Chongqing 400074 Peoples R China Chongqing Open Univ Sch Urban Construct Engn Chongqing 401520 Peoples R China

Owing to the complex composition of the internal structures of aged crumb rubber-modified asphalt (CRMA), the current understanding of its aging properties and mechanism is lacking. Therefore, this study used the Christensen-Anderson-Marasteanu model, established the master curves of the complex moduli and phase angles of aged CRMA samples, and analyzed the evolution of their viscoelastic properties. Moreover, gel permeation chromatography and scanning electron microscopy were used to characterize the microscopic characteristics of the asphalt and crumb rubber modifier (CRM) phases of the CRMA samples. In aging, the evolution process of the complex modulus and phase angles of CRMAs demonstrated three stages in the low-frequency domain. With the degradation of the CRM, the plateau in the master curves of the phase angles gradually disappeared and the slopes of the Han curves gradually increased. The plateau of phase angle and slope of the Han curve were used as indices to evaluate the degradation of the CRM in the aged CRMA. The microscopic tests demonstrated that the further degradation effect of the CRM degradation products decreased the weight-average molecular weight of the aged CRMA. In addition, the degradation of the CRM probably affected the formation of asphaltene and reduced its content. The CRM of the unaged CRMA exhibited a fluffy structure similar to that of a sponge. As the aging time increased, the surface of the CRM tended to be smooth, the pore structure disappeared, and finally, the fluffy structural form of the CRM disappeared.

关键词： Crumb rubber-modified asphalt binder multiphase microstructure Aged asphalt Viscoelastic properties

来源：评论

学校读者我要写书评

暂无评论

Ultra-high strength and high ductility 60Si2CrVNb spring steel with multiphase microstructure controlled by austempering

引用

JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T 2024年 30卷 5855-5868页

作者： Li, Yunchao Wang, Engang Zhang, Lin Zhao, Xue Gao, Rui Zhu, Wenna Northeastern Univ Key Lab Electromagnet Proc Mat Minist Educ Shenyang 110819 Liaoning Peoples R China Northeastern Univ Sch Met Shenyang 110819 Peoples R China

In this study, a series of austempering treatments were carried out on the designed novel 60Si2CrVNb spring steel and the effects of different austempering temperatures on the microstructure and mechanical properties of the steel were studied. The results show that after austempering treatments, the microstructure of 60Si2CrVNb spring steel exhibited a multiphase microstructure composed of martensite, bainite and retained austenite (RA). As the austempering temperature increased, the proportion of martensite gradually decreased, while the proportion of bainite significantly increased, and the proportion of RA first increased and then slightly decreased. The carbon content and stability of RA gradually increased. The toughness and ductility of steel gradually increased, while the strength decreased gradually. At the austempering temperature of 240 degrees C for 90 min, due to the presence thin and long lath bundles of martensite and bainite, as well as the effective synergy between multiphase microstructure, the spring steel exhibited excellent comprehensive properties with an ultimate tensile strength of 2578 MPa, a total elongation of 11.2 %, an impact toughness of 11.8 J, and PSE of 28.6 GPa%. After the austempering treatment at 350 degrees C for 90 min, the highly stable RA in the spring steel exhibited a sustained TRIP effect during the tensile process. The RA gradually transformed into twinned martensite, enabling the spring steel to exhibit a long-lasting work hardening capacity and achieve excellent toughness and ductility, resulting in a total elongation of 24.1 %, an impact toughness of 29.2 J, and a PSE of 36.4 GPa%.

关键词： 60Si2CrVNb spring steel Austempering multiphase microstructure Retained austenite

来源：评论

学校读者我要写书评

暂无评论

Fatigue crack propagation behavior of multiphase microstructure in a quenched and partitioned medium-carbon bainitic steel

引用

FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES 2023年第1期46卷 325-340页

作者： Li, Qiangguo Zhang, Yanan Luo, Hong Sichuan Univ Failure Mech & Engn Disaster Prevent Key Lab Sich Chengdu Peoples R China Xian Aeronaut Univ Sch Mat Engn 259 West Second Ring Rd Xian 710077 Shaanxi Peoples R China Sichuan Univ Coll Architecture & Environm MOE Key Lab Deep Earth Sci & Engn Chengdu 610065 Peoples R China Xihua Univ Minist Educ Key Lab Fluid & Power Machinery Chengdu 610039 Peoples R China Mat Corros & Protect Key Lab Sichuan Prov Zigong 643002 Peoples R China

A medium-carbon steel was treated by the bainitic isothermal transformation plus quenching and partitioning (B-QP) process to obtain bainite/martensite/retained austenite multiphase microstructure, and its fatigue crack propagation (FCP) behavior was evaluated in contrast with BAT (bainite austempering) sample with fully bainite microstructure. Results show that B-QP sample exhibits a lower FCP rate and higher fatigue threshold Delta K-th (12.6 MPa center dot m(1/2)). Moreover, the FCP path of B-QP sample displays a strongly tortuosity and more crack branching due to more filmy retained austenite (7.2%) and higher percentage of high angle misoriented boundaries (68%). The larger crack tortuosity and the secondary cracks as result of crack branching are primarily responsible for the lower FCP rate of B-QP sample. In addition, the FCP rate curve of B-QP sample shows a pronounced small plateauing at the near-threshold zone, which can be ascribed to the mechanical twinning that occurred in the filmy retained austenite.

关键词： bainitic steel fatigue crack propagation mechanical twinning multiphase microstructure retained austenite

来源：评论

学校读者我要写书评

暂无评论

Impact abrasive wear behaviour of the multiphase microstructure in a medium carbon quenched and partitioned bainitic steel

引用

WEAR 2023年第1期518卷

作者： Li, Qiangguo Zhang, Yanan Luo, Hong Sichuan Univ Sch Mech Engn Chengdu 610065 Peoples R China Xian Aeronaut Univ Sch Mat Engn Xian 710077 Peoples R China Sichuan Univ Failure Mech & Engn Disaster Prevent Key Lab Sichu Chengdu 610065 Peoples R China Sichuan Univ MOE Key Lab Deep Earth Sci & Engn Chengdu 610065 Peoples R China Xihua Univ Key Lab Fluid & Power Machinery Minist Educ Chengdu 610039 Peoples R China Mat Corros & Protect Key Lab Sichuan Prov Zigong 643002 Peoples R China Sichuan Univ Sch Mech Engn South Sect 1 24 Yihuan Rd Chengdu 610065 Sichuan Peoples R China

To enhance the impact abrasive wear resistance of steel for mining and metallurgy industries, a 0.3C steel with a multiphase microstructure of bainitic, martensitic and retained austenite was produced by a Q&P process involving bainitic transformation, and its wear performance under impact abrasive conditions was evaluated in contrast with fully martensitic and fully bainitic steels. The results revealed that the multiphase microstructure demonstrates outstanding combination of strength (1612 MPa), toughness (105 J), hardness (48.7 HRC) and elongation (19.2%), along with superior impact abrasive wear resistance. After 90 min of impact abrasive wear test, the multiphase microstructure shows lower wear loss than that for the fully martensitic and fully bainitic steels, which can be attributed to its high surface microhardness and increased toughness. The formation of nanograins and an increase in dislocation density as well as the retained austenite transformation leads to the higher surface microhardness. In addition, some larger craters can be observed on the wear surface of fully martensitic and fully bainitic steels, and the crack propagation depth is larger under the wear surface. In contrast, the wear surface of the multiphase microstructure presents some delamination damage, and the crack propa-gation depth is shallow because of the thicker deformed layer and presence of film-like austenite retained in the deformed microstructure. These results suggested that the multiphase microstructure can be used as a potential candidate structure for enhanced resistance to impact abrasive wear.

关键词： Impact abrasive wear multiphase microstructure Quenched and partitioned bainitic steel Retained austenite Hardness and toughness

来源：评论

学校读者我要写书评

暂无评论

Experimental research and application of cold cutting to hot stamping parts based on multiphase microstructure

引用

Baosteel Technical Research 2023年第3期17卷 1-8页

作者： WU Yanjun LUO Aihui WANG Chenlei Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai 201999China State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel) Shanghai 201999China

Among the bottlenecks that hinder the improvement of the production efficiency of hot stamping are high strength and difficulty in edge cutting and hole *** from the preparation of hot stamping multiphase microstructure materials,this paper developed a plate quenching die system with controllable surface temperature and prepared four types of hot stamping plates with different martensite volume ***,straight edge cold cutting experiments were performed to study the influence of cutting clearance and cutting force on fracture *** results show that the bright zone is the largest when the cutting clearance is 0.14 mm,and the cutting experience coefficient of the hot stamping sheet with each martensite volume fraction is obtained when the cutting clearance is 0.14 *** research results of this paper were applied to the production of hot stamping parts.

关键词： hot stamping cold cutting multiphase microstructure

来源：评论

学校读者我要写书评

暂无评论

Fatigue property and microstructure deformation behavior of multiphase microstructure in a medium-carbon bainite steel under rolling contact condition

引用

INTERNATIONAL JOURNAL OF FATIGUE 2019年 125卷 381-393页

作者： Li, Qiangguo Huang, Xuefei Huang, Weigang Xian Polytech Univ Sch Mat Sci & Engn Xian 710048 Shaanxi Peoples R China Sichuan Univ Coll Mat Sci & Engn 24South Sect 1Yihuan Rd Chengdu 610065 Sichuan Peoples R China

Bainitic steel is considered to be the best potential candidate steel for rails due to its high strength and excellent toughness. The objective of this work was to investigate the fatigue property and microstructure deformation behavior of a medium-carbon bainitic steel with bainite/martensite/retained austenite multiphase microstructure obtained by a modified Q&P process (B-QP) under rolling contact condition. The analysis results of TEM indicated that the multiphase microstructure consists of lath bainitic ferrite, lath martensitic ferrite and film-like retained austenite which distributes mainly between bainite and martensite laths. The results showed that the multiphase microstructure has a better combination of toughness (103 J), hardness (47.8 HRC) and elongation (18.6%), along with better rolling contact fatigue (RCF) properties and wear resistance than that of full bainite microstructure obtained by the austempering process (BAT). After the steel subjected to 10(5) cycles of RCF testing, nanocrystalline grains (approximately 93 nm and 67 nm for the BAT and B-QP sample, respectively) were obtained at the deformed layer depth of 10 mu m. Meanwhile, the multiphase microstructure demonstrated a higher microhardness increasing ratio (24.5%) than that of the full bainite (21.2%) and a larger plastic deformation zone (103 mu m). The EBSD and XRD analysis indicated that the multiphase microstructure has a lower stress concentration possibility and higher percentage of high-angle boundaries as well as some film-like austenite retained in the plastic deformation layer. In addition, many pits on the contact surface of the BAT sample appeared, due to spalling damage caused by cyclic loading, and the crack propagation depth was larger. Conversely, the contact surface of the B-QP sample with a multiphase microstructure looked smooth, and the crack propagation depth was shallow under the contact surface. The enhanced rolling contact fatigue properties and wear resistance o

关键词： multiphase microstructure Bainitic steel Fatigue damage Wear microstructure deformation

来源：评论

学校读者我要写书评

暂无评论

multiphase microstructure in a Metastability-Assisted Medium Carbon Alloy Steel

引用

JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE 2018年第7期27卷 3239-3247页

作者： Liu, Cheng Cui, Xixi Yang, Chen Yangzhou Univ Coll Mech Engn Yangzhou Jiangsu Peoples R China

A medium carbon alloy steel is processed by austenizing at 900 A degrees C for 30 min, then rapid quenching into a patented quenching liquid and holding at 170 A degrees C for 5 min, finally isothermally holding at 250 A degrees C for different times. The morphology and mechanical properties are performed by using optical microscopy and scanning electron microscopy. A multiphase microstructure characterized by a mixture of lenticular prior martensite (PM), fine needle bainitic ferrite and filmy retained austenite (RA) is obtained. It is found that the PM formed firstly upon quenching can accelerate the subsequent bainitic transformation and promote refinement of multiphase colonies. The results show that an optimum mechanical property of a 4000.9 MPa bending strength and a 2030 MPa tensile strength is achieved at 250 A degrees C for 120 min, which is attributed to the multiphase microstructural characteristics and a high product of the volume fraction of RA and the carbon content of austenite.

关键词： isothermal heat treatment multiphase microstructure prior martensite property

来源：评论

学校读者我要写书评

暂无评论

Effect of multiphase microstructure on fatigue crack propagation behavior in TRIP-assisted steels

引用

INTERNATIONAL JOURNAL OF FATIGUE 2020年第0期133卷 105425-000页

作者： Song, Chenghao Wang, Haoliang Sun, Zhenzhong Wei, Zhengying Yu, Hao Chen, Haibin Wang, Yanlin Lu, Jun Dongguan Univ Technol Sch Mech Engn 1 Daxue Rd Dongguan 523808 Guangdong Peoples R China Xi An Jiao Tong Univ Sch Mech Engn 28 Xianning West Rd Xian 710049 Shaanxi Peoples R China Univ Sci & Technol Beijing Sch Mat Sci & Engn 30 Xueyuan Rd Beijing 100083 Peoples R China

The effect of various multiphase microstructures on the fatigue properties of intercritical annealing, quenching and partitioning (I&Q&P) steel, transformation-induced plasticity (TRIP)-assisted annealed martensite (TAM) steel and TRIP steel was investigated by S-N curve, fatigue crack growth (FCG) rate and in-situ scanning electron microscopy tests. The fatigue limits of I&Q&P, TAM and TRIP steels, determined by a derivation of the Stromeyer relationship, are 670 MPa, 770 MPa and 795 MPa, respectively. The region II of FCG curve was fitted by Paris and exponential models, and the result indicates that I&Q&P steel has the highest FCG rate, followed by TAM steel and TRIP steel. In I&Q&P steel, fatigue crack mainly propagates along the interfaces between ferrite and martensite or ferrite and martensite and austenite islands, resulting in the presence of many secondary cracks;in TAM steel, the fatigue crack propagation (FCP) can be retarded when the crack passes through the mixed microstructure containing annealed martensitic laths and film-like retained austenite at an angle (not parallel);in TRIP steel, the crack branching and interlocking can hinder the FCP effectively, benefitting from bainite densely distributing in ferrite matrix as strengthening phase and the two phases having almost identical grain size. Therefore, the multiphase microstructure of TRIP steel has the best effect on retarding FCP among the three steels. The findings are essential for the optimization of multiphase microstructure in designing a steel with excellent fatigue properties.

关键词： multiphase microstructure Steel Fatigue limit Martensite Fatigue crack propagation

来源：评论

学校读者我要写书评

暂无评论

Strain hardening behavior and deformation characteristics of multiphase microstructure in a medium-carbon quenching and partitioning bainitic steel

引用

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES microstructure AND PROCESSING 2017年 707卷 199-206页

作者： Li, Qiangguo Huang, Xuefei Huang, Weigang Sichuan Univ Coll Mat Sci & Engn 24South Sect 1Yihuan Rd Chengdu 610065 Sichuan Peoples R China

A 0.3C-1.4Si-1.8Mn (wt%) steel was subjected to a modified Q & P process leading to the formation of a multiphase microstructure comprising bainite, martensite and retained austenite. The strain hardening behavior and deformation characteristics of the multiphase microstructure were investigated by tensile tests and electron backscattered diffraction (EBSD), respectively. The results show that the multiphase microstructure containing about 50% bainite exhibits a better combination of strength (1617 MPa), elongation (18.6%), the product of strength and elongation (PSE, 30.1 GPa%) and toughness (103 J) compared to the fully bainite. The strain hardening exponent-strain curves indicate that the multiphase microstructure has a much broader strain hardening plateau and the strain hardening exponent calculated for the multiphase microstructure and fully bainite is 0.085 and 0.064, respectively. The analysis results of EBSD demonstrate that the local stress concentration of the multiphase microstructure mainly appears in martensite and the bainite/martensite interfaces, and can more effectively spread to the interior of bainite with deformation increasing. In addition, the more low Taylor Factor regions under the large deformation condition and some retained austenite grain rotation can be observed in the multiphase microstructure. These caused better plastic deformation of multiphase microstructure with subsequent improvement in ductility.

关键词： multiphase microstructure Retained austenite Q & P Strain hardening behavior Deformation characteristics

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：