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Effects of Ni content and tempering temperatures on microstructure and properties of medium-carbon cast steel

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Journal of Iron and Steel Research International 2023年第8期30卷 1524-1536页

作者： Xiao-bo Cui Tian-long Liu Zhi-bin Zheng Zhi-qiang Guo Kai-hong Zheng Pei-xian Han School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870LiaoningChina Institute of New Materials Guangdong Academy of SciencesNational Engineering Research Center of Powder Metallurgy of Titanium and Rare MetalsGuangdong Provincial Key Laboratory of Metal Toughening Technology and ApplicationGuangzhou 510651GuangdongChina Guangdong Provincial Iron Matrix Composite Engineering Research Center Guangzhou 510651GuangdongChina Jiangxi Lianfeng Investment Casting Co. Ltd.Yichun 336300JiangxiChina

The microstructure evolution and properties of medium-carbon cast steel alloyed with different Ni contents after tempering at various temperatures have been *** addition of 0.47-1.59 wt.%Ni content results in the formation of 16%-36% retained austenite(RA).The blocky and irregular-polygonal RA mainly forms along the prior austenite grain boundaries,and the tempering temperature does not affect the RA *** hardness of medium-carbon cast steel is affected by the precipitation of carbides and the hardness of *** RA content is the main cause of intergranular impact rupture and low impact *** long-strip carbides formed after tempering at 320℃ would further reduce the impact energy of medium-carbon cast *** tempering at 220 and 380℃,the increase in impact energy is attributed to the formation of rod-like and spherical carbides and the low-carbon *** the medium-carbon cast steel with high impact energy,its impact-abrasive wear resistance is more ***-cutting and delamination are the primary wear mechanisms.

关键词： Medium-carbon cast steel Ni content Tempering temperature Hardness impact energy impact-abrasive wear resistance

Damage and penetration behavior of aluminum foam at various impacts

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Journal of Central South University 2014年第9期21卷 3442-3448页

作者： CHO Hosun CHO Jaeung Division of Mechanical Engineering Graduate School Kongju National University Division of Mechanical and Automotive Engineering Kongju National University

In this work, the damage and penetration behavior of aluminum foam at various types of impact were examined through experiments. The impact energy of a striker was applied on the fixed aluminum foam having a thickness of 25 mm while increasing its impact by 2 J at each strike from 6 J to 16 J. The results show that the impact energies from 6 J to 12 J could not penetrate aluminum foam. However, the aluminum foam applied with the impact energy of 12 J incurred severe damages on its lower part. Finally, the aluminum foam applied with the impact energy of 14 J was penetrated. The striker having the impact energy of 6 J could penetrate aluminum foam around 10 mm. At this moment, aluminum foam could absorb the impact energy of around 9 J. When the impact energy of 14 J was applied on the aluminum foam, the aluminum foam was penetrated and it absorbed the impact energy of around 17.2 J. It is possible to create the safer structure against impact using the results of this work. The simulation results for the verification of the experimental results imply that the results for all the experiments in this work are reliable. It is possible to predict the structural safety of the aluminum foam for an impact if the impact behavior of aluminum foam performed in this work is utilized.

关键词： aluminum foam absorbed energy finite element analysis impact energy impact load

Effect of Microalloying Additions on the Microstructure and Mechanical Properties of Low Carbon Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 246-251页

作者： EISSA Mamdouh ABD El-Aziz Ahmed GHALI Saeed HALFA Hossam SABER Shady Central Metallurgical Research & Development Institute "CMRDI" Faculty of Material Science and Engineering German University in Cairo "GUC"

Low carbon steels are characterized by good weldability,formability and fracture toughness ***,the low strength levels of these steel grades limit their wide *** the other hand,increasing the strength by increasing the carbon content and alloying elements deteriorates the other *** this study,the microalloying technique was used to examine the possibility of attaining low carbon steels with good combination of strength,ductility and impact properties.A low carbon steel microalloyed with single addition of vanadium and another one microalloyed with combined addition of vanadium and titanium were used in this investigation and their properties were compared with non-microalloyed low carbon steel having the same base ***,other two nonmicroalloyed and V-microalloyed steels with higher carbon,silicon and manganese contents were also investigated to reveal the effect of base ***,hardness,room and zero temperature Charpy V-notch impact tests were conducted to evaluate the variations in the mechanical properties of low carbon hot forged steel containing vanadium and combinations of vanadium and *** addition,the microstructures of the different investigated steels were observed using both optical microscope and scanning electron ***,the hardness of the ferrite phase was also determined using micro-hardness *** results showed improvement of the mechanical properties of the investigated steels by both single V-and combined V + ***,hardness and impact tests results indicated that good combinations of strength,ductility and impact properties can be achieved by V-microalloying *** with combination of V and Ti microaddition has much higher hardness,yield strength,ultimate tensile strength and impact energy at both room and zero temperatures compared with non-microalloyed and single Vmicroalloyed *** C,Si and Mn contents result in

关键词： low carbon steels single microalloying combined microalloying strength ductility impact energy grain refinement precipitation strengthening

Effect of secondary weld thermal cycle on structure and properties

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China Welding 2001年第2期10卷 16-20页

作者：魏金山张田宏 Luoyang Ship Material Res. Institute Luoyang 471039 China

This paper deals with structure and impact energy of weld HAZ of 10CrNi3MoV steel after secondary weld thermal cycle (t_ 8/5 =8 s ～120 s ; peak temperature T_ m =750 ℃ ～1 300 ℃ ). It is demonstrated that the coarse grain and structure produced by first thermal cycle keep unchanged after secondary thermal cycle above Ac_ 1 critical temperature but below 1 050 ℃ . At the same time the low temperature impact energy decreases obviously with increasing t_ 8/5 . By metallurgical microscope and transmission electron microscope(TEM) , it is revealed that the effect of coarse grain and structure caused by secondary thermal cycle on low temperature impact energy.

关键词： secondary thermal cycle over-heated zone impact energy

Influence of Pseudoelasticity on Mechanical Behavior of TiNi Alloy under Dynamic impact Loading

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Petroleum Science 2007年第1期4卷 86-89页

作者： Xu Renbo Cui Lishan Zheng Yanjun Chen Hongling Department of Materials Science and Engineering China University of Petroleum Beijing 102249 China

The mechanical behavior of TiNi alloy and Cr12MoV alloy under dynamic impact loading was investigated with a self-made impact testing system. The real-time contact force was measured with a piezoelectric force sensor and digital signal processing system during impact. Equations for predicting instantaneous velocity anti displacement were presented. The results showed that the TiNi alloy exhibited a plateau of maximum contact force with increasing impact height. At the plateau stage, TiNi alloy in the parent phase can absorb impact energy and keep the maximum contact force nearly identical due to its pseudoelasticity.

关键词： TiNi alloy mechanical behavior contact force impact energy pseudoelasticity

The welding application of high strength steels used in engineering machinery

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China Welding 2021年第1期30卷 57-64页

作者： Cui Bing Yan Peipei Du Quanbin Yang De Cui Mengshuan Peng Mengdu School of Materials Science and Engineering Anhui University of TechnologyMa’anshan 243023China State Key Laboratory of Advanced Steel Processes and Products Central Iron&Steel Research InstituteBeijing 100081China Henan Key Laboratory of Intelligent Manufacturing Equipment Integration for Superhard Materials Henan Mechanical and Electrical Vocational CollegeZhengzhou 451191China

With the rapid development of low alloy steel strength level,more problems caused by welding are exposed day by ***,the efforts have been paid to improve or enchance the low toughness of heated affected zone and welded metal which can enchance the comprehensive mechanical properties that is the core scientific problems of its safe operation by researching crack initiation and crack propragation attracted a rapidly growing *** article focuses on the research status and progress of welding technology and joint microstructure and properties of advanced steel *** influence of shielding gas on the microstructure evolution of deposited metals,the effect heat input of welded joint performance,interpass temperature and alloy elements on welded joints microstructure and M-A constituent evolution and properties are reviewed in *** for the heat affected zone,the grain size and microstructure as well as the shape,size,and distribution of M-A constituent,have a significant impact on the impact *** paper is an attempt to review the effect of different welding process parameters on welded metal and HAZ of HSLA steels.

关键词： High strength low alloy steel heat affected zone impact energy microstructures M-A constituents

Material development for a sustainable precast concrete block pavement

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Journal of Traffic and Transportation Engineering(English Edition) 2016年第5期3卷 483-491页

作者： R.Bharathi Murugan C.Natarajan Shen-En Chen Department of Civil Engineering National Institute of TechnologyTiruchirappalli 620015India Department of Civil and Environmental Engineering University of North Carolina at CharlotteCharlotteNC 28223USA

Portland cement concrete （PCC） and asphalt concrete （AC） are the most common roadway and highway construction materials which are more suitable for continuous slab pave- ments. The durability of these materials is highly dependent on construction quality and techniques, and both materials are difficult to repair. Heavy rain storms in India have recently revealed several roadway pavement failures and resulted in significant repair costs. Interlocking block type pavements are simpler to construct and maintain than both PCC and AC pavements but, have only been used for slower traffic roads due to weak interlocking at the joints. To improve the quality of block pavements, blocks made of PCC with waste tire crumb rubber partially replacing river sand （fine aggregate） are suggested. The joint interlocks can be further improved by modifying the block geometry. The material is completely recycled and is deemed more superior than concrete pavements when repair and construction techniques and costs are concerned. This paper presents the material characterization of Rubberized Concrete Blocks （RCBs） using crumb rubber particle size ranging from 0.075 mm to 4.75 mm to partially replace the fine aggregates. It also discusses the advantages of RCB over continuous material pavements.

关键词： Rubberized concrete Crumb rubber Damage mechanism Material characterization impact energy

Mechanical characterization of sisal reinforced cement mortar

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Theoretical & Applied Mechanics Letters 2014年第6期4卷 26-30页

作者： R.Fujiyama F.Darwish M.V.Pereira Department of Mechanical Engineering Para Federal University Department of Civil Engineering Fluminense Federal University Department of Materials Engineering Catholic University of Rio de Janeiro

This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.

关键词： composite material impact energy fracture initiation J-integral

Dynamic regimes of cemented backfill at early-age

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Journal of Central South University 2021年第7期28卷 2079-2090页

作者： LIU Zhi-yi GAN De-qing GAN Ze School of Mining Engineering North China University of Science and TechnologyTangshan 063210China Development and Safety Key Lab of Hebei Province Tangshan 063210China Department of Science and Technology North China University of Science and Technology Tangshan 063210China

In view of the mechanics characteristic of cemented tailings backfill(CTB)at early age,the separation Hopkinson pressure bar test device was used to explore the effects of curing age and impact energy.A total of 48 CTB samples with diameter of 50 mm and length of 25 mm were prepared with curing ages of 3,5,7 and 9 *** tests under different impact energy(10,20,30 and 40 J)were carried *** microstructure of CTB at different ages was analyzed by scanning electron microscopy(SEM).The results show that,the curing age mainly affects the mechanical properties and internal structure of early-age *** increasing curing age,the mechanical properties of early-age CTB change from viscoelasticity to *** impact energy mainly affects the response of dynamic peak compressive strength to strain *** low strain rate,the structure of CTB is broken,but still has bearing capacity,affecting the formation of later *** is concluded that the structural loses completely under the action of high strain ***,the control of impact energy and the protection of curing age should be fully considered in actual production process.

关键词： early-age backfill curing age impact energy mechanical property microstructure analysis