凝固模拟与优化分析在叶轮轮毂铸件上的应用

针对“东保供水工程”用叶轮毂铸件中产生的缩孔、缩松等缺陷，应用FT－Star凝固模拟软件直观、定量地预测了铸件的缩孔、缩松缺陷，实现了叶轮轮毂铸造工艺的优化设计，提高了铸件的质量。     

消失模壳体类零件在白区工艺的失效模式分析及改进

针对壳体类零件在消失模铸造过程中存在的尺寸不稳定、碳缺陷、变形等问题成立了质量小组，对白区的一些工艺参数进行了分析和验证。研究了模样的质量特性参数与铸件缺陷之间的关系，寻找最佳参数组合。以达到降低基于模样质量导致铸件缺陷的绝对数量，提升合格率。     

球铁铸件的"花斑"缺陷及其防止技术

通过对球铁铸件加工面上发现“花斑”缺陷原因的机理分析。试验研究了在化学成分的调整、碳硅当量的控制以及配料、球化、孕育等方面采取的措施。消除了球铁铸件“花斑”缺陷，从而保证了铸件生产的质量。     

均衡凝固理论在厚实板类铸件上的应用

厚实板类铸件按传统工艺生产，容易产生缩孔，缩凹，缩松，夹砂，胀包等铸造缺陷，应用均衡凝固理论进行工艺设计，能解决该类铸件上述缺陷，提高铸件质量和企业经济效益。     

客车制动盘铸造工艺模拟与优化分析

本文针对高速铁路客车ＳＷ－１６０转向架用制动盘铸件产生的缩孔、缩松等缺陷，结合现场铸造工艺情况，运用ＰｒｏＣＡＳＴ软件成功地预测了缺陷的位置与尺寸，实现了制动 主铸件质量的改进。     

球墨铸铁铸造质量的无损检测综合评价方法

介绍了各种无损检测技术用于球墨铸铁质量检测的基本原理及应用状况。液体渗透检测、涡流检测和磁粉检测常用于检测铸件表面和近表面缺陷，射线检测和超声检测常用于检测铸件内部缺陷，超声检测还可用于表面光洁铸件的球化质量的检测，振动检测则用于表面粗糙铸件的球化质量的检测。     

冷硬树脂砂铸造铝镁合金铸件的质量控制

从提高铝镁金铸件质量出发，分析研究了冷硬树脂砂的工艺特点，采用冷硬树脂砂铸型和差压浇注等方法，获得了优质铸件。现场浇注铸件测试结果表明，铝镁合金铸件精度可达ＣＴ７－９级，表面粗糙度Ｒａ＝４．５，铸件无内部缺陷。     

厚实床身的铸造工艺

床身是锻压机床上的重要零件，系大断面厚实铸件。生产中因铸件较厚实易产生缩孔、缩松等缺陷。通过拼型组芯造型、利用浇注系统补缩、采取低温慢浇和充分补浇等工艺措施，保证了床身铸件的质量。     

汽车铸件的质量控制

介绍了汽车铸件生产过程质量控制的详细内容:包括铸造生铁、废钢、硅铁、锰铁及球化剂等铸造原辅材料的质量控制、型砂处理、造型、制芯、熔炼、浇注等工序质量控制、铸件材料质量、铸件尺寸、外观质量、铸件内部缺陷等质量控制。由于严格控制生产过程的结果,铸件废品率、铸件材料消耗、能耗等指标都逐年降低。     

铸钢叉车用桥壳的质量控制

针对叉车用铸钢桥壳的质量问题，如裂纹、气孔等缺陷，通过在配料和熔炼工艺，造型、制芯及合箱等方面加以控制，使得铸钢桥壳的质量大为改善。同时制定了铸钢桥壳缺陷允许焊补的条例，规范了铸件缺陷处理。     

呋喃树脂砂铸件常见缺陷及防止措施

呋喃树脂砂铸件质量一般比黏土砂铸件好，但如果原材料选择、工艺设计、造型和制芯操作不当。也会产生气孔、粘砂、脉纹、裂纹、夹渣、硬度不足、渗碳、渗硫和球化不良等铸造缺陷。对这些缺陷的产生原因进行了分析，并提出了相应的防止措施。     

High-quality manufacturing method of complicated castings based on multi-material hybrid moulding process

A multi-material hybrid patternless moulding process for complicated castings has been proposed. Moulding sands used in the hybrid moulding process include silica sand, ceramic sand, chromite sand, zircon sand, and steel shot sand. Experimental method was used to study the effects of moulding sands on the temperature field, mechanical properties, and dimensional precision of the iron castings. Under the condition that the wall thickness on different sides of the casting is the same, when the wall thickness is greater than 10 mm, the heat storage capacity of the moulding sands from strong to weak is steel shot sand, zircon sand, chromite sand, ceramic foundry sand, and silica sand. Tensile strength of the obtained castings from high to low is zircon sand, chromite sand, steel shot sand, ceramic sand, and silica sand. Contraction rate of the obtained castings from high to low is steel shot sand, zircon sand, chromite sand, silica sand, and ceramic sand. Therefore, steel shot sand and zircon sand can be used as chilled sand, and even can be used instead of cold iron when the casting wall thickness is greater than 10 mm. Zircon sand and chromite sand can be used to obtain high mechanical properties, and silica sand and ceramic sand can be selected to obtain high dimensional precision of the castings. Finally, a typical iron casting piece was tested by experiment using the hybrid moulding process. Excellent performances of iron castings confirm the feasibility of the hybrid moulding process.     

铁型覆砂铸造及其发展

铁型覆砂铸造是指在金属型（铁型）内腔覆上一薄层树脂砂，然后采用这种覆砂铁型浇注铸件。原来主要用于球铁曲轴，现已扩大应用到50余种（类）铸件。由于覆砂铁型刚度较高，用于球铁件能实现无冒口铸造．提高工艺出品率，并能提高铸件尺寸精度，改善表面质量。笔者介绍铁型覆砂工艺的基本原理、发展情况以及计算机凝固模拟在该工艺上的应用。     

湿型球墨铸铁件收缩特性的试验研究

采用正交试验的方法，浇注一系列铸件，测量铸件的冷却曲线；解剖铸件，测定铸件质量、铸件及缩孔体积。研究了碳当量、孕育、铸件模数以及铸型条件对湿型球铁件收缩特性及缩孔缩松的影响。为开展数值模拟预测球铁件缩孔、缩松的工作打下了基础。     

Effect of cooling rate and of titanium additions on the microstructure of thin-walled compacted iron castings

This article addresses the effect of cooling rate and of titanium additions on the exhibited microstructure of thin-walled compacted graphite iron (TWCI) castings as determined by changing moulding media, section size and ferrotitanium. Various moulding materials were employed (silica sand and insulating sand ‘‘LDASC’’) to achieve different cooling rates. This study shows that the cooling rates exhibited in the TWCI castings varies widely (70–14 °C/s) when the wall thickness is changed from 2 to 5 mm. In turn, this is accompanied by a significant variation in the compacted graphite fraction. The resultant cooling rates were effectively reduced by applying an insulating sand in order to obtain the desired graphite compactness. Ti additions in combination with LDASC sand moulds were highly effective in promoting the development of over 80% compacted graphite in castings with wall thicknesses of 2–3 mm as evidenced by quantitative metallographic analyses.     

大型轴承箱体铸件粘砂和油槽不通的工艺改进

介绍了大型轴承箱体铸件的结构和技术要求,详细阐述了原生产工艺及油槽处存在的粘砂和铁包砂问题,对缺陷位置进行原因分析后,采取了相应的防止措施:在原工艺的基础上,调整浇注系统,控制浇注温度,采用保温冒口材料制作镶嵌结构的油槽芯。生产结果显示:铸件表面良好,内部光滑,有效解决了扁而宽大油槽部位易产生粘砂、铁包砂的问题。与原工艺相比,铸件易于清理,达到了使用要求,又降低了铸件清理工作量,显著提高了箱体铸件的成品率。     

Dynamic measurements of the load on castings and the contraction of castings during cooling in sand molds

The load on flange castings in sand molds was gradually increased beginning from the end of the solidification process until the final cooling stage. The maximum tensile load on the flange castings in furan sand molds was larger than that of the flange castings in green sand molds. With the furan sand mold, permanent deformation in the flange castings occurred beginning from the end of the solidification process until reaching a temperature of approximately 250 °C. The mechanical interaction between the casting and the sand mold should be considered for more accurate stress calculations, particularly in furan sand molds.     

Impact properties of A356-T6 alloys

The Charpy impact energy of A356 alloys has been measured. Instrumented Charpy impact tests have been conducted at 25,100,150, and 200 °C. The Charpy specimens were machined from plate castings ortapered cylindrical castings. The plates were produced in sand molds, and tapered cylinders were produced in water-cooled copper molds. Both unmodified and strontium-modified castings were tested. The results indicate that strontium modification improves the impact properties of sand and permanent mold castings. The impact energy increases with solution treatment time. Strontium modification reduces the solution treatment time for attaining a specific impact property level in the casting.     

大型铸钢件造型和制芯工艺的选用

简述了大型铸钢件造型和制芯工艺的现状,着重分析了碱性酚醛树脂砂、呋喃树脂砂和酯硬化水玻璃砂的造型工艺特点,从型砂配比、硬化性能、型砂性能、铸件质量、旧砂回用、劳动环保、经济评价和工艺评价等方面对三种型砂工艺进行了对比,为生产大型铸钢件时自硬砂造型和制芯工艺的选择提供参考。     

The Influence of Processing Variables on the Dimensional Integrity of Spheroidal-graphite Iron Castings

Abstract

This investigation was carried out to identify the major factors and their degree of influence on the dimensional accuracy of spheroidal-graphite iron castings produced in chemically- bonded sand moulds. Test castings were poured into furan-resin-bonded zircon sand and silica sand moulds and sodium silicate/ CO₂ bonded silica sand moulds. A comparison of casting sizes with those of the mould cavity into which they were poured showed considerable scatter and overlap. From these data the size that each casting would have had, had it solidified without graphite formation, was calculated and found to depend on mould cavity size for each type of mould. By isolating the differences in casting size due to graphite it was possible to identify the influencing factors. Thus castings poured into furan-resin-bonded zircon sand have the highest contraction and their size depends primarily on the amount of graphite present. The dimensions of castings poured into silica sand moulds show more variation and depend not only on the amount of graphite present and the structure of the metal but also on the thermal expansion of the silica sand moulds.