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Effect of vibration frequency on primary phase and properties of grey cast iron fabricated by lost foam casting

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China Foundry 2020年第1期17卷 1-7页

作者： Bo-tao Xiao Zi-tian Fan Wen-ming Jiang Jun-huai Xiang Xue-fang Yan Jiangxi Key Laboratory of Surface Engineering Jiangxi Science and Technology Normal UniversityNanchang 330013China State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science&TechnologyWuhan 430074China

The properties of gray cast iron(GCI)are affected by density of matrix,size of flake graphite and primary *** this paper,the Y-type specimen of GCI was prepared by lost foam casting(LFC)with and without vibration,and the influence of vibration frequency on the density of matrix,size of primary phase,and properties of the GCI was *** results show that the length of the flake graphite and the size of the primary austenite in GCI firstly decrease and then increase with the increase of the vibration *** a vibration frequency of 35 Hz,the length of the flake graphite is the shortest,the primary austenite is the finest and the density of the matrix is the *** addition,the tensile strength,elongation and hardness of the GCI firstly increase and then decrease with the increase of the vibration frequency,due to the refinement of the primary phase and the increase of the matrix *** order to analyze the refinement mechanism of the primary phase of the GCI fabricated by the LFC with vibration,the solidification temperature fields of the GCI fabricated by the LFC with the vibration frequency of 0 and 35 Hz were *** results show that the vibration reduces the eutectic point of the GCI and increases the supercooling degree during the eutectic *** a result,the length of the flake graphite and the size of the primary austenite in GCI fabricated by LFC with the vibration frequency of 35 Hz decrease.

关键词： vibration frequency lost foam casting grey cast iron flake graphite properties

Niobium alloying effect in high carbon equivalent grey cast iron

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China Foundry 2011年第1期8卷 36-40页

作者： Zhou Wenbin Zhu Hongbo Zheng Dengke Zheng Hongxing Hua Qin Zhai Qijie Shanghai Key Laboratory of Modern Metallurgy ＆ Materials Processing Shanghai University Shanghai 200072 China Shanghai Huizhong Automotive Manufacturing Co. Ltd. Shanghai 200072 China Instrumental Analysis ＆ Research Center Shanghai University Shanghai 200072 China

The effect of niobium on the formation of NbC phase and solidification structure in high carbon equivalent grey cast iron was *** experimental results indicated that an increase in the niobium content is favorable to refining the graphite and eutectic cell;and the pearlite lamellar spacing is *** on the thermodynamic calculation the formation of NbC is prior to the eutectic *** reduction in the pearlite lamellar spacing is mainly attributed to the decrease of eutectic temperature with the addition of ***,properties including hardness and wear resistance were improved after the addition of niobium.

关键词： niobium alloying grey cast iron high carbon equivalent refinement

THERMAL FATIGUE AND FRACTURE MECHANICS ANALYSIS OF grey cast iron

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Acta Metallurgica Sinica(English Letters) 1989年第3期2卷 194-200页

作者： GUO Chengbi ZHOU Weisheng Dalian Institute of Technology,Dalian,Liaoning,China Professor,Dept.of Shipbuilding,Dalian Institute of Technology,Dalian,Liaoning,China

The in-phase and out-of-phase thermal fatigue,the C-P type and P-C type isothermal fa- tigue of grey cast iron were experimentally *** fatigue life was evaluated analytically by using the elastic-plastic fracture mechanics method(mainly J integral).The results of ex- periments and calculations showed that the lifes of in-phase and C-P type fatigue are longer than that of out-of-phase and P-C type fatigue respectively within the same strain range. This is in contrast to the results of other materials such as low carbon *** the other hand, the predicted lifes are consistent with experimental *** suggests that J integral as a mechanics parameter for characterizing the thermal fatigue strength of grey cast iron and the mechanics model and the calculation method developed here are efficient.A parameter ΔW_1 was proposed from energy aspect to characterize the capacity of crack propagation. The isothermal fatigue life is the same as the thermal fatigue life for identical ΔW_1 values.

关键词： grey cast iron thermal fatigue fracture

Research on Welding Test of grey cast iron and Low-Carbon Steel

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厦门大学学报（自然科学版） 2002年第S1期41卷 300-页

作者： LIU Cui-rong 1,ZHAO Zhi-ying 2 (1.Taiyuan Heavy Mach.Inst.,Taiyuan 030024,China 2.Taiyuan Chemical Factory,Taiyuan 030021,China)

grey cast iron’s welding itself is a complex proble *** proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks will *** p reheating before weldingslow cooling after welding and other welding procedure are taken,the grey cast iron side can probably be *** the carbon wi ll diffuse to HAZ of the low-carbon steel side more *** after stud ying the weldabilities of grey cast iron and low-carbon steel,the author develo ped a new type of cast iron electrode considering the demands of factories’prac tices,and the welding technology test of grey cast iron and low-carbon steel ar e carried out. In this paper,a new type of grey cast iron electrode is developed based on the practices in factories,its ingredients and properties are *** w elding tests of grey cast iron and low-carbon steel are *** joint str ucture of the dissimilar metal and the appearance of weld are *** hard ness distribution of the welded joint is *** results show that the elect rode can meet the welding requirements of the grey cast iron and low-carbon stee *** are no cracksgas pores and other defects of metallurgy in welded join t,the appearance of welded joint are good.

关键词： grey cast iron low-carbon steel welding

Research on Welding Test of grey cast iron and Low-Carbon Steel

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Research on Welding Test of Grey Cast Iron and Low-Carbon St...

Molybdenum alloying in cast iron and steel

第十届国际制造工程与管理会议

作者： LIU Cui-rong ZHAO Zhi-ying( 1. Taiyuan Heavy Mach . Inst. Taiyuan 03p024 China 2. Taiyuan Chemical Factory Taiyuan 030021 China)

＜正＞ grey cast iron’s welding itself is a complex problem. So proper welding materials must be selected, complex welding techniques such as preheating before welding, slow cooling after welding etc, should be taken . However the carbon component in low-carbon steel is comparatively low , the carbon of welded joint will diffuse to the low-carbon steel when it is welded with grey cast iron, which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ, high carbon martensite and cracks will occur. If preheating before welding, slow cooling after welding and other welding procedure are taken, the grey cast iron side can probably be qualified. But the carbon will diffuse to HAZ of the low-carbon steel side more easily. Therefore after studying the weldabilities of grey cast iron and low-carbon steel, the author developed a new type of cast iron electrode considering the demands of factories’ practices, and the welding technology test of grey cast iron and low-carbon steel are carried *** this paper, a new type of grey cast iron electrode is developed based on the practices in factories , its ingredients and properties are introduced. The welding tests of grey cast iron and low-carbon steel are practiced . The joint structure of the dissimilar metal and the appearance of weld are observed. The hardness distribution of the welded joint is tested. The results show that the electrode can meet the welding requirements of the grey cast iron and low-carbon steel. There are no cracks..gas pores and other defects of metallurgy in welded joint, the appearance of welded joint are good.

关键词： grey cast iron low-carbon steel welding

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Advances in Manufacturing 2020年第1期8卷 3-14页

作者： Xiang-Ru Chen Qi-Jie Zhai Han Dong Bao-Hua Dai Hardy Mohrbacher School of Materials Science and Engineering Shanghai UniversityShanghai 200444P.R.China CITIC Machinery Manufacturing Inc. Houma 043011ShanxiP.R.China Department of Materials Engineering KU LeuvenLeuven 3001Belgium NiobelCon bvba Schilde 2970Belgium

Metal casting is an important manufacturing technology for efficiently producing massive components with complex shape.A large share of industrial castings is made from iron and steel alloys,combining attractive properties and low production *** of properties in cast iron and steel is mainly achieved by alloying and in fewer cases by heat *** is an important alloying element in that respect,increasing strength,hardness and *** also facilitates particular heat treatments such as *** paper describes the metallurgical functionality of molybdenum alloying in iron-based castings and demonstrates its effectiveness for applications in the automotive and mining industry.

关键词： grey cast iron Nodular iron Pearlite Austempering Creep resistance Wear resistant alloys Hardness Toughness Mining industry Automotive industry

Study on in-situ WC particles/tungsten wire reinforced iron matrix composites under electromagnetic field

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China Foundry 2010年第2期7卷 157-162页

作者： Niu Libin Xu Yunhua Wu Hong College of Materials Science and Engnieering Xi ＂an University of Science and Technology Xi＇an 710055 China Institute of Wear- Resistance Materials College of Mechanical and Electrical Engineering Xi ＇an University of Architecture ＆ Technology Xi ＇an 710055 China

By applying electromagnetic field to a system consisting of tungsten wires and grey cast iron melt,the grey cast iron matrix composite reinforced by either in-situ WC particles or the combination ofin-situ WC particles and the residual tungsten wire was *** means of differential thermal analysis(DTA),the pouring temperature ofiron melt was determined at 1,573 *** microstructures of the composites were analyzed by using of X-ray diffraction(XRD),scanning electron microscopy(SEM) equipped with an energy dispersive spectrum(EDS) and pin-on-disc abrasive wear *** obtained results indicated that,with the enhancing frequency of electromagnetic field,the amount ofin-situ WC particles gradually increases,leading to continuous decrease of the residual tungsten *** the electromagnetic field frequency was up to 4 kHz,tungsten wires reacted completely with carbon atoms in grey cast iron melt,forming WC *** electromagnetic field appeared to accelerate the elemental diffusion in the melt,to help relatively quick formation of a series of small FeW-C ternary zones and to improve the kinetic condition ofin-situ WC *** compared with the composite prepared without the electromagnetic field,the composite fabricated at 4 kHz presented good wear resistance.

关键词： tungsten carbide particle composite electromagnetic field in-situ synthesis grey cast iron

Defect elimination in green sand casting using simulation techniques:A case study

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第5期11卷 1-19页

作者： Sarabjit Singh Neeraj Sharma Rajesh Khanna Department of Mechanical Engineering DAV University Jalandhar 144012PunjabIndia Department of Mechanical Engineering Maharishi Markandeshwar(Deemed to be University)Mullana 133207 AmbalaIndia International Tractors Ltd. HoshiarpurPunjabIndia

The Reynolds number of molten metal flowing mold cavity causes bulk turbulence and is the main cause of defects like shrinkage porosity and sand *** housings with shrinkage porosity at critical bearing bores and surface made the casting *** old gating casting areas of perimeters 290mm and 264mm of transmission housing,Reynolds numbers were observed as 16307 and 13806,respectively using simulation *** were collected from experiments to change casting area perimeters from 785mm and 785mm along with the addition of overlap *** Reynolds numbers at two locations were observed as 3705 and 3393,*** metal pressure,velocity and temperature results were related for final shrinkage results of the components on full *** purpose of the study is to reduce shrinkage and porosity defects in green sand casting part using MAGMAS simulation *** outcome was the reduction of casting machining rejection in transmission housing casting from 5.8%0.7%with savings of approximately 0.13 million USD over the period of 14 *** of this work include casting defects study and reduction in different grades and weight range.

关键词： Green sand casting gating system Reynolds number grey cast iron shrinkage porosity MAGMAS software

Optimization of casting conditions for heat and abrasion resistant large grey iron castings

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China Foundry 2007年第2期4卷 124-127页

作者： S. M. Yoo Y. S. Cho C. C. Lee J. H. Kim C. H. Kim J. K. Choi Center for e-Design Korea Institute of Industrial TechnologyYeonsugu Sondodong 7-47Incheon 406-800Korea Kwanghee casting Mfg. Co. Seogu Kyungseodong 381-75Incheon 404-170Korea R&D Center Doosan Engine Co. Ltd. Sinchondong 69-3 Changwon 641-370 Korea

Numerical simulation technology was applied for optimizing the casting design and conditions in large cast iron castings for marine engine. By the simulation of mold filling and solidification sequences the problems of the previous casting conditions were analyzed and marked improvements for large cylinder liner parts were derived from these results. Especially the amount and positions of chills were optimized to increase the mechanical properties and to minimize the shrinkage and microporosity in the castings. Ultrasonic testing, penetration testing and mechanical property testing were carried out for the parts with the modified casting conditions. It showed that no defects in the castings were found and the productivity could be distinctly increased. The mechanical properties satisfied also the specification demanded.

关键词： grey cast iron numerical simulation marine engine cylinder liner chill casting design optimization