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Filling mode and regularity of vertical centrifugal casting process of titanium alloy in thin-walled cylinder cavity
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作者 Qin Xu Xing Wang +1 位作者 Yong-gang Guo Shi-ping Wu 《中国铸造:英文版》 SCIE 2019年第2期105-109,共5页
The mold filling process of titanium alloy in a thin-walled cylinder cavity under vertical centrifugal casting process was studied by means of the hydraulic simulation experiments. Results show that the filling mode o... The mold filling process of titanium alloy in a thin-walled cylinder cavity under vertical centrifugal casting process was studied by means of the hydraulic simulation experiments. Results show that the filling mode of the melt in the cylinder cavity varies with casting wall-thickness. When the casting wall-thickness is less than or equal to the thickness of the first layer during the filling process, the melts fill the cavity from the bottom to the top.When the casting wall-thickness is greater than the thickness of the first layer during the filling process, the melts first fill the largest radius parts of the cavity with a certain thickness of the first layer from the bottom to the top of the cavity, and then they fill the cavity from the larger radius part to the smaller radius part. The melt filling ability increases with the increment of the mold rotational speed and the pouring temperature. In another aspect, the melt filling ability rises with the decrement of the melt viscosity, and the melt with the better filling ability is prone to fill the cylinder cavity layer by layer. 展开更多
关键词 titanium alloy THIN-WALLED CASTING vertical CENTRIFUGAL CASTING cylinder-shape CAVITY hydraulic experiment mold FILLING
Effect of continuous casting speed on mold surface flow and the related near-surface distribution of non-metallic inclusions 预览
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作者 Peng Fei Yi Min +1 位作者 Cheng-jun Liu Mao-fa Jiang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第2期186-193,共8页
For the control of surface defects in interstitial-free(IF)steel,quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted.The r... For the control of surface defects in interstitial-free(IF)steel,quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted.The results show that,at casting speeds of 0.8 and 1.0 m/min,a thin liquid mold flux layer forms and non-uniform floating of argon bubbles occurs,inducing the entrainment and subsequent entrapment of the liquid flux;fine inclusion particles of Al2O3 can also aggregate at the solidification front.At higher casting speeds of 1.4 and 1.6 m/min,the liquid mold flux can be entrained and carried deeper into the liquid steel pool because of strong level fluctuations of the liquid steel and the flux.The optimal casting speed is approximately 1.2 m/min,with the most favorable surface flow status and,correspondingly,the lowest number of inclusions near the slab surface. 展开更多
关键词 non-metallic INCLUSIONS DISTRIBUTION CASTING SPEED surface flow
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Research on surface defects and continuous casting process of Fe-Ni alloy 预览
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作者 GUO Liangliang XU Zhengqi LU Jiansheng 《宝钢技术研究:英文版》 CAS 2019年第1期17-24,共8页
Over the last decade,various Fe-Ni alloys have been developed at Baosteel using the EAF AOD LF VD CC route. This paper first reveals the main cause of defects in Fe-Ni alloys,including surface edge cracks on hot-rolli... Over the last decade,various Fe-Ni alloys have been developed at Baosteel using the EAF AOD LF VD CC route. This paper first reveals the main cause of defects in Fe-Ni alloys,including surface edge cracks on hot-rolling strips and slivers on cold-rolling strips of Fe-36%Ni alloy.Then,the material properties and in-situ solidification behavior were experimentally investigated.The gas content and average diameter of the inclusions in Fe-36%Ni alloy that occur along the EAF AOD LF VD CC route were also investigated via potentiostatic electrolysis using a non-aqueous organic electrolytic.Furthermore,the heat transfer and solidification in a continuous casting mold were predicted based on an inverse heat transfer model using the measured mold temperature.Experimental results show that the gas content,which is <0.001 5% in a continuous casting slab,and the average diameter of the inclusions both decrease during the metallurgical EAF AOD LF VD CC process.The average diameter of the inclusions in a continuous casting slab is ~18 μm, which tends to induce slivers during subsequent cold-rolling process.Experimental in-situ solidification results show that the mushy zone between the liquidus and solidus of Fe-Ni alloy is much narrower than that of plain carbon steel.Stresses are generated during continuous casting,primarily due to the thermal contraction of a few percentage points,and any strain applied to the steel within this temperature region will cause cracks to propagate outward from the solidification front between the dendrites.Numerical simulation results illustrate that heat flux and shell thickness are uneven across the width of the mold,particularly the shell thickness close to the edge of the slab surface in the fixed face is 6-mm thinner than that at the slab center.Based on these results,the incidence of surface defects in Fe-Ni alloy can be greatly reduced by the adjustment and optimization of its refining and continuous casting process. 展开更多
关键词 CONTINUOUS CASTING SURFACE EDGE cracks slivers FE-NI ALLOY
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Molten steel level stability in continuous casting slab mold under electromagnetic stirring 预览
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作者 WEN Hongquan WU Cunyou ZHOU Yueming 《宝钢技术研究:英文版》 CAS 2019年第1期25-31,共7页
Fluctuation of molten steel level in continuous casting process is a critical issue.The analytic function for the liquid steel surface stability index( F ) of the continuous casting slab mold under the action of elect... Fluctuation of molten steel level in continuous casting process is a critical issue.The analytic function for the liquid steel surface stability index( F ) of the continuous casting slab mold under the action of electromagnetic stirring was derived.The effects on the F value of the electromagnetic field,casting mold,submerged entry nozzle,and casting speed were observed,and the stability of the process parameters of a practical continuous casting system was evaluated.The main results generated are as follows:① Based on the free flow jet theory,a formula is established for the level stability index of continuous casting slab mold under electromagnetic stirring.② According to the results of calculation,the various parameters in decreasing order of the magnitude of their influence are magnetic flux density,nozzle submersion depth,casting speed,slab width,stirring current frequency,and nozzle side-hole inclination angle.③ For practical continuous casting with a slab thickness of 230 mm,the calculated F values are between 3 and 5 for different matches between slab width and casting speed,but the parameter optimization space is much larger for wider slab widths and lower casting speeds. 展开更多
关键词 LEVEL STABILITY free flow jet electromagnetic STIRRING F -index continuous casting mold
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浅谈铸件质量问题的分析 预览
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作者 刘建勇 周林勇 +1 位作者 刘建雄 涂彩云 《铸造工程》 2019年第1期20-23,共4页
阐述了对铸件质量问题的认知,对铸件质量问题进行分析的必要性、难点和方法。介绍了编制分析报告的步骤及铸件质量分析时易产生的差错和注意事项。
关键词 铸件 质量 原因 措施
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ZG08Cr12Ni1铁素体热强钢铸件热处理制度与组织、性能研究 预览
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作者 肖章玉 马正强 +2 位作者 曾国成 刘显有 王海英 《大型铸锻件》 2019年第2期31-34,共4页
研究了热处理制度对大型核电汽轮机缸体铸件材料ZG08Cr12Ni1组织和力学性能的影响。结果表明:高温扩散退火在细化晶粒,降低δ-铁素体含量方面有明显的作用;提高正火温度对提高材料强度有明显作用,冲击吸收能有所下降;经过两次高温奥氏体... 研究了热处理制度对大型核电汽轮机缸体铸件材料ZG08Cr12Ni1组织和力学性能的影响。结果表明:高温扩散退火在细化晶粒,降低δ-铁素体含量方面有明显的作用;提高正火温度对提高材料强度有明显作用,冲击吸收能有所下降;经过两次高温奥氏体化,其晶粒更细,δ-铁素体含量降低;去应力炉冷降温,其冲击吸收能大幅下降。通过试验,掌握了热处理制度对该材料组织和性能的影响,确定了最佳的热处理制度。 展开更多
关键词 ZG08Cr12Ni1 铸件 热处理 组织 力学性能
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Interface reaction during titanium alloys investment casting by residue gas in ceramic mold
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作者 Ya-Meng Wei Zhi-Gang Lu +1 位作者 Xin-Yi Li Xin Guo 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第4期327-335,共9页
The chemical reaction between mold material and titanium melt during investment casting was studied intensively. However, the in fluence of residue gas in ceramic mold on interface reaction remains unclear. In this in... The chemical reaction between mold material and titanium melt during investment casting was studied intensively. However, the in fluence of residue gas in ceramic mold on interface reaction remains unclear. In this investigation, the effect of residue gas in Y2O3-silica sol shell mold on interface reaction during Ti-6A1-4V alloy investment casting was investigated. Two groups of shell molds were prepared by adding different kinds of pore formers, i.e., spherical starch particles or nylon fibers, respectively. Ti-6Al-4V alloy was cast under vacuum by gravity casting through cold crucible induction melting (CCIM) method. Porosity of different shell molds was measured based on Archimedean method. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to characterize the micromorphology and composition of the reaction area, respectively. White light interferometer (WLI) was used to obtain the surface topography of the shell mold. The results show that the direct chemical reaction is very weak for all specimens. The release of residue gas in closed pores is the key factor influencing surface defects. However, open pores make nearly no difference on the interface reaction. 展开更多
关键词 Titanium alloy Investment CASTING RESIDUE GAS Y2O3: SILICA sol
复杂曲面钛合金叶轮消失模铸造工艺研究 预览
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作者 史昆 鲁玲玲 +1 位作者 赵军 刘时兵 《铸造》 CAS 北大核心 2019年第4期344-346,共3页
复杂曲面钛合金叶轮铸件采用机加工石墨铸型或熔模精密铸造方法生产成本高、周期长。利用消失模工艺方法,生产出复杂曲面的钛合金叶轮铸件,而且化学成分和力学性能测试均满足使用要求,具有低成本、质量高、生产周期短的优势。
关键词 铸造 消失模 钛合金 叶轮
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压气机导叶用GTD222合金铸造技术研究 预览
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作者 李建中 《模具制造》 2019年第4期89-92,共4页
阐述了航空发动机用耐高温材料的研究进展,论述了GTD222合金试制工艺、热物性参数以及微观组织,并对GTD222合金的热物性参数进行了计算,为后续GTD222压气机导叶铸件浇注系统的设计与数值模拟提供了关键参数。
关键词 压气机 GTD222合金 铸造 研究
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Multi-objective model and optimization algorithm based on column generation for continuous casting production planning
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作者 Jian Yi Shu-jin Jia +1 位作者 Bin Du Qing Liu 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2019年第3期242-250,共9页
The optimization of continuous casting production planning(CCPP)in the steel industry was studied.The essence of CCPP is the productive capability balance of back-end facilities over the planning time period.The facil... The optimization of continuous casting production planning(CCPP)in the steel industry was studied.The essence of CCPP is the productive capability balance of back-end facilities over the planning time period.The facilities with the demands of productive capability are called the flows.On the basis of charge plans,the task of CCPP is to produce cast plans according to the rules of cast design in order to meet the flows.Firstly,a multi-objective model was established with considering the demands of flows,the capability requirements of liquid steel refini ng devices,and the rules of cast design.Secondly,the model was decomposed into a master problem(set partitioning problem model)and a series of subproblem(pricing problem model)by using Dantzig-Wolfe decomposition strategy.Finally,a column generation-based optimization algorithm(CGBOA)was presented.The experimental results on practical production data from Baosteel demonstrate that the proposed algorithm is effective and feasible.Moreover,a new decision support system based on CGBOA has been successfully established and applied to No.2 Steelmaking Plant at Baosteel. 展开更多
关键词 STEELMAKING Continuous CASTING Production planning CHARGE CAST COLUMN generation
铝合金铸件国内外射线检测标准对比
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作者 王海登 王伏喜 +1 位作者 张克俭 鄂楠 《铸造技术》 CAS 2019年第1期112-115,共4页
概述了国内外铝合金铸件射线检测标准发展和应用情况。通过对比各个标准的关键技术要求,分析了标准中关于射线源、透照工艺和底片质量要求的差别,并重点讨论了质量分级方法。最终结合当前射线检测的技术现状对标准的整体情况进行了归纳... 概述了国内外铝合金铸件射线检测标准发展和应用情况。通过对比各个标准的关键技术要求,分析了标准中关于射线源、透照工艺和底片质量要求的差别,并重点讨论了质量分级方法。最终结合当前射线检测的技术现状对标准的整体情况进行了归纳,旨在为国内相关标准的修订提供参考。 展开更多
关键词 铝合金 铸件 射线检测 标准
激光诱导击穿光谱诊断合金铸件表面/界面质量 预览
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作者 刘正 贾云海 +1 位作者 韩凤奎 吴剑涛 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第2期596-606,共11页
熔模精密铸造技术广泛应用于高温合金叶片生产。高温合金单晶叶片铸件尺寸精度高,内部和表面不得有缺陷,但在浇铸时易受浇铸温度场、熔体流场及与模壳发生界面反应的影响而导致表面结瘤、凹陷、缩孔等缺陷。激光诱导击穿光谱(LIBS)是一... 熔模精密铸造技术广泛应用于高温合金叶片生产。高温合金单晶叶片铸件尺寸精度高,内部和表面不得有缺陷,但在浇铸时易受浇铸温度场、熔体流场及与模壳发生界面反应的影响而导致表面结瘤、凹陷、缩孔等缺陷。激光诱导击穿光谱(LIBS)是一种非常有效的表面及界面分析技术,对于诊断分析铸件表面/界面质量具有明显的优势,对样品损伤小,可对不平整表面进行分析。研究优化了LIBS深度分析的条件,采用2mm孔径光阑分光,500mJ,1 064nm脉冲高斯激光在焦外激发单晶高温合金获得了良好的空间分辨力,降低了能量密度较低的二级以上衍射环能量辐射造成表层烧蚀引起的深度分析信号失真。体积烧蚀速率与激光输出能量线性正相关,与光阑直径正相关,与激发频率无关。采用LIBS技术对DD407高温合金单晶叶片表面和近表面进行了深度分析。发现SiO2-Al2O3莫来石结构的型壳在铸造过程中会引起DD407单晶叶片表面和近表面的Al,Ti,Ni,Cr,Co贫化,其中Al和Ti贫化显著且深度达50μm。铸件尖锐部位较厚大部位的合金元素贫化明显。叶片经过脱芯脱壳后表面沉积钙镁盐类、钠盐物质。通过沸水清洗和超声清洗后,钠盐完全去除,钙镁物质均大幅减少,仍有3~5μm厚。LIBS可方便的进行合金铸件表面和界面的成分分布分析,给出表面/界面质量的清晰判据,展现了较好的应用前景。 展开更多
关键词 激光诱导击穿光谱 深度分析 高温合金 单晶叶片 铸件 表面质量 合金贫化
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“使用与满足”视角下的移动视频直播发展研究 预览
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作者 王绍忠 谢文博 《吉林师范大学学报:人文社会科学版》 2019年第1期88-94,共7页
在科技迅速发展和商业利益的驱动下,移动视频直播逐渐兴起。由于移动视频直播完全实现实时互动、准入门槛低导致其内容良莠不齐、缺乏深度与广度以及信息的失真,故只有在结合使用与满足理论的基础上增加差异化内容、丰富视频直播产业链... 在科技迅速发展和商业利益的驱动下,移动视频直播逐渐兴起。由于移动视频直播完全实现实时互动、准入门槛低导致其内容良莠不齐、缺乏深度与广度以及信息的失真,故只有在结合使用与满足理论的基础上增加差异化内容、丰富视频直播产业链、加强对内容的监督管理才可能有效地改善移动视频直播现存的问题,推动移动视频直播朝着利好方向不断发展。 展开更多
关键词 使用与满足 信息传播 新媒体 移动视频直播 发展研究
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铁路货车高质量心盘铸件制造工艺 预览
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作者 毕红雪 李福胜 《铸造》 CAS 北大核心 2019年第1期23-28,共6页
介绍了一种铁路货车心盘的生产实践。在多年货车心盘生产的基础上,设计了满足AAR M201 B+级钢心盘的冶炼、铸造、热处理工艺及工装。经模拟计算和生产验证,生产的心盘符合质量标准。
关键词 心盘 铸造 热处理工艺
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Microstructure and Mechanical Properties of Mg–RE–TM Cast Alloys Containing Long Period Stacking Ordered Phases: A Review
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作者 Huan Liu He Huang +4 位作者 Jia-Peng Sun Ce Wang Jing Bai Ai-Bin Ma Xian-Hua Chen 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第3期269-285,共17页
Casting magnesium alloys hold the greatest share of magnesium application products due to their short processing period, low cost and near net shape forming. Compared with conventional commercial magnesium alloys or o... Casting magnesium alloys hold the greatest share of magnesium application products due to their short processing period, low cost and near net shape forming. Compared with conventional commercial magnesium alloys or other Mg–RE-based alloys, the novel Mg–RE–TM cast alloys with long period stacking ordered(LPSO) phases usually possess a higher strength and are promising candidates for aluminum alloy applications. Up to now, two ways: alloying design and casting process control(including subsequent heat treatments), have been predominantly employed to further improve the mechanical properties of these alloys. Alloying with other elements or ceramic particles could alter the solidifi cation pattern of alloys, change the morphology of LPSO phases and refi ne the microstructures. Diff erent casting techniques(conventional casting, rapidly solidifi cation, directional solidifi cation, etc.) introduce various microstructure characteristics, such as dendritic structure, nanocrystalline, metastable phase, anisotropy. Further heat treatments could activate the transformation of various LPSO structures and precipitation of diverse precipitates. All these evolutions exert great impacts on the mechanical properties of the LPSO-containing alloys. However, the underlying mechanisms still remain a subject of debate. Therefore, this review mainly provides the state of the art of the casting magnesium alloys research and the accompanying challenges and summarizes some topics that merit future investigation for developing high-performance Mg–RE–TM cast alloys. 展开更多
关键词 MAGNESIUM alloys Long period STACKING ORDERED PHASE CASTING Heat treatment PHASE TRANSFORMATIONS Mechanical properties
Microstructure and properties of ductile iron bars for plunger pump prepared by horizontal continuous casting process
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作者 Chun-jie Xu Zhen Zhao +4 位作者 Yu Lei Yong-hui Liu Zhong-ming Zhang Yan Li Dan Shechtman 《中国铸造:英文版》 SCIE 2019年第2期118-125,共8页
Ductile iron bars(DIBs) with a diameter of 145 mm, used for plunger pump production, were made by the horizontal continuous casting(HCC). The microstructure of the samples cut at three locations with different distanc... Ductile iron bars(DIBs) with a diameter of 145 mm, used for plunger pump production, were made by the horizontal continuous casting(HCC). The microstructure of the samples cut at three locations with different distances away from the surface(~20 mm from the surface, half of the radius and the center of the HCCDIBs)were investigated. The mechanical properties were measured by tensile and torsion tests. Results show that after the spheroidization of graphite, the iron matrix incorporates the nodules of Format I, Size 8 close to the surface, Format I, Size 7 at the half of the radius from the surface, and Format II, Size 6 in the centre of the bar,according to the ASTM A247 standard. The content of pearlite in the matrix changes from 55%(~20 mm from the surface) to 70%(half of the radius) and 80%(the center of the HCCDIBs). The strengths in tension are 552, 607 and 486 MPa with the elongations of 12.5%, 10.5% and 5.8% in samples cut at these three locations from the surface to the centre, respectively. The strength in torsion is equal to 558, 551 and 471 MPa at corresponding torsion angles of 418°, 384° and 144° respectively to the same distance from the bar surface. Fracture in tension is manifested via crack propagation through the interface between graphite nodules and matrix(Mode I), while in torsion the fracture is caused by the shear of graphite nodules(Mode II). It is shown that the transition between two fracture modes is also dependent on the size of graphite nodule. Typically, fracture Mode I was observed for nodules of smaller diameter(less than 22.7 μm) and fracture Mode II was seen for nodules of greater diameter(more than 24.8 μm). 展开更多
关键词 HORIZONTAL continuous casting DUCTILE iron BARS PLUNGER pump tension and TORSION properties microstructure
用TRIZ方法求解铸造成本高的问题 预览
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作者 王有 刘丽娟 《铸造设备与工艺》 2019年第1期47-50,共4页
某公司新上了一套铸造生产线,生产之初成本居高不下。通过成本分析,发现原辅材料为其主要原因。针对这个问题利用TRIZ方法进行功能分析、因果分析,通过技术矛盾,物理矛盾,及功能裁剪寻找一些解决方案,最后根据现场实际进行方案评价选择... 某公司新上了一套铸造生产线,生产之初成本居高不下。通过成本分析,发现原辅材料为其主要原因。针对这个问题利用TRIZ方法进行功能分析、因果分析,通过技术矛盾,物理矛盾,及功能裁剪寻找一些解决方案,最后根据现场实际进行方案评价选择出可行性方案,并在生产中进行试验应用。 展开更多
关键词 铸造 降成本 TRIZ创新方法 树脂固化剂
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双相不锈钢导叶体铸造工艺设计及实践
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作者 陈亚涛 钟玉平 +1 位作者 郭绪镇 李镜银 《材料开发与应用》 CAS 2019年第1期28-32,共5页
导叶体是喷水推进装置中动力系统的关键部件,具备典型的大型薄壁复杂曲面结构特点,其尺寸公差、形位公差、重量公差等级高,相比例控制严格,组织要求高度致密,铸造难度极大。通过合理设计铸件的浇、冒口工艺和激冷系统,借助国际先进的3D... 导叶体是喷水推进装置中动力系统的关键部件,具备典型的大型薄壁复杂曲面结构特点,其尺寸公差、形位公差、重量公差等级高,相比例控制严格,组织要求高度致密,铸造难度极大。通过合理设计铸件的浇、冒口工艺和激冷系统,借助国际先进的3D打印技术打印砂芯,控制合金成分和固溶温度以及采用AOD精炼炉精炼等措施,导叶体铸件一次性铸造成功,质量符合控制规范的要求。 展开更多
关键词 导叶体 铸造 工艺 相比例 缺陷
砂型铸造砂铁比降低方法研究 预览
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作者 杨磊 马瑞 +1 位作者 李文辉 韩庆文 《中国铸造装备与技术》 CAS 2019年第1期34-36,共3页
随着目前铸造市场形势的变化,原辅材料价格的不断上涨以及铸件价格的下降,砂铁比已经成为铸造生产中降低生产成本的一项非常重要的指标,降低砂铁比即降低型砂用量,同时降低树脂固化剂的使用量及再生砂的周转效率。主要通过近几年降低砂... 随着目前铸造市场形势的变化,原辅材料价格的不断上涨以及铸件价格的下降,砂铁比已经成为铸造生产中降低生产成本的一项非常重要的指标,降低砂铁比即降低型砂用量,同时降低树脂固化剂的使用量及再生砂的周转效率。主要通过近几年降低砂铁比工作经验的总结,通过对产品进行结构分类,对各类产品总结出一套降低砂铁比的工装设计方法及操作方法,为后期降低砂铁比工作提供指导。 展开更多
关键词 砂铁比 铸造 再生砂
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铸造CAE技术在大型球铁件中压外缸产品工艺设计中的应用 预览
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作者 张龙江 姚红汝 《中国铸造装备与技术》 CAS 2019年第1期45-49,共5页
介绍了一种大型球铁件中压外缸的铸造结构及技术要求,利用CAE技术,将多种工艺方案可能产生的缺陷问题进行模拟分析,找到产生缺陷的根本原因,并提出了改进方案,解决了中压外缸铸造过程中的缩松与探伤等问题。
关键词 CAE技术 铸造 模拟分析 工艺设计
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