离心铸造高铬铸铁复合轧辊试验研究

高铬铸铁是一种良好的抗磨材料,并具有一定的韧性和耐蚀性,因此可用作湿摩擦条件下的耐磨工件。本文研究确定了离心铸造高铬铸铁复合辊套的工艺措施;分析了适用于双金属离心铸造工艺特点的高铬铸铁的成分;对于膨胀系数相差较大的双金属复合辊套,根据离心铸造的特点,采用早出模、先空冷后保温的工艺方法,达到了对复合辊套进行淬火和回火的目的。     

金属型铸造高铬铸铁Cr20组织及性能的研究

研究了金属型铸造高铬铸铁Cr20的铸态组织和性能,以及主要合金元素对性能的影响。结果表明,用金属型铸造的高铬铸铁Cr20的铸态组织为奥氏体基体,共晶碳化物为孤立的块状分布,具有较高的硬度和一定的韧性,并且还可以降低合金元素Mo和Ni的加入量。对于不能通过常规热处理进行淬火硬化的高铬铸铁件,可用金属型铸造来满足在铸态下使用的要求。     

球铁铝锭模材料热疲劳性能的研究

模拟铝锭模的使用条件,研究了不同基体组织球墨铸铁的热疲劳性能.结果表明,退火铁素体铝铸锭模使用寿命最长.该铝锭模安装在包头铝业公司的2台铝锭连续铸造机上使用,平均每天铸锭48t/台,连续使用410天.而普通材质的球铁铝锭模使用寿命仅为120到150天左右.     

高硅合金耐热铸铁生产球墨铸铁模具的研制

对铸铁模具使用工况进行了分析,采用了高硅合金耐热铸铁为生产球墨铸铁模具的材质,并介绍了高硅合金耐热球墨铸铁模具的消失模铸造工艺、冶炼工艺、热处理工艺以及该材质模具的实际使用效果。实际生产表明：高硅合金耐热球墨铸铁具有优越的综合耐热疲劳性能,大大提高了模具寿命。     

Solidification microstructure of M2 high speed steel by different casting technologies

The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies,namely iron mould casting and continuous casting.The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks,which were greatly refined in the ingot made by continuous casting process,compared with that by the iron mould casting process.M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods.In the ingot by iron mould casting,they have a plate-like morphology and grow anisotropically.However,in the ingot made by continuous casting,the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth.It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated,as a result,the carbides refined remarkably,compared with the case of plate-like carbides in the iron mould casting ingot.     

灰口铸铁件残余应力的测量与消除

铸件的残余应力影响其尺寸稳定性和性能,甚至会导致铸件失效.采用盲孔法测定铸态、退火态和铸造后砂型保温的灰口铸铁件试样的残余应力.试验结果表明,砂型保温工艺和退火处理一样,能有效地降低铸铁件的残余应力,而且该法工艺简单、成本较低.     

Technical divergence observed in the microstructure of bronze artifacts from the Great Hwangnam Tomb in Kyongju,Korea

Metallurgical examination of bronze artifacts from the Great Hwangnam Tomb in Kyongju, Korea, shows that they were either cast or forged from unleaded alloys containing relatively low or negligible Sn. This clearly deviates from the early Korean bronze tradition based on casting and leaded high Sn alloys, and is also distinguished from the later tradition characterized by the use of high Sn alloys and various thermo-mechanical treatments after casting. This divergence was a transient episode leading to the nucleation of a new bronze tradition in Korea. It is suggested that the spread of iron use and the resulting demand for new bronze items served as major factors driving the search for new metallurgical techniques.     

飞轮壳的铸造工艺设计

HT250飞轮壳铸件采用HWS静压线造型、湿型砂铸造工艺。根据铸件的结构特点,把整个铸件放置在下型,法兰边向上,每型布置两件,上型砂胎喷涂涂料防止粘砂。浇注系统各单元截面尺寸为:∑F阻=13.5 cm2,F直=19.63 cm2,∑F内=31.68 cm2,∑F网=77 cm2。生产结果表明,飞轮壳铸件满足顾客要求。     

球墨铸铁耙片挤压铸造新工艺

给出了挤压铸造球墨铸铁耙片的新型模具结构、工艺参数和应用效果.模具设有冷却水道和铁水溢流槽.为在耙片上铸出通孔,凸模和凹模分别设有浮动型芯.经试验,挤压铸造的球墨铸铁耙片力学性能好,生产成本低.     

D型石墨灰铸铁气缸的金属型重力铸造

介绍气缸金属型重力铸造工艺设计的经验,针对生产中发生的缩孔、缩松、渣孔、气孔缺陷制定合理的控制措施.采用水冷金属型铸造,并加入合金元素增大铁液过冷倾向,获得D型石墨铸铁,用以生产空调器压缩机气缸,其金相组织和性能均达到技术要求.     

铁型覆砂铸造磨球工艺的试验研究

应用铁型覆砂铸造技术和计算机仿真技术，研究了铁型覆砂铸造磨球工艺的原理，按照生产线标准研制了铁型覆砂铸造贝氏体球铁磨球工艺装备和试验装置，进行了现场工艺试验，获得了关键工艺参数数据。试验结果表明，新工艺生产的磨球尺寸精度可以达到CT6级，表面粗糙度达到Ra12．5，球铁材质铸态硬度（HRC）平均值为32～34，直径60mm磨球的工艺出品率达到70％，生产工序少、周期短，适合机械化生产线方式进行大规模生产。     

工艺条件对WC/高铬铸铁铸渗效果的影响

高铬铸铁铸渗碳化钨制备的复合材料有利于解决特殊工况条件下零部件磨损异常突出的问题，但前提条件是要达到良好的铸渗效果。作者就浇注系统、浇注温度、型腔气压、铸渗层厚度等工艺参数对铸渗效果的影响进行了试验研究。结果表明，在适宜的铸造工艺条件下，碳化钨颗粒和高铬铸铁基体之间可以形成良好的冶金结合，铸渗效果较好。     

结晶冷却速度对中铬铸铁组织和性能的影响

通过采用砂型和金属型铸造的方法,研究了结晶冷却速度对中铬铸铁铸态组织和性能的影响。试验结果表明:提高结晶冷却速度可以使中铬铸铁的组织明显细化,特别是奥氏体一次、二次枝晶间距显著减小;(Fe,Cr)3C型碳化物含量增多,碳化物尺寸减小,综合力学性能得到提高。     

球铁卡块铸件均衡凝固工艺与品质控制

采用铸铁件均衡凝固工艺,内浇口多道分散均匀引入铁液,热侧冒口补缩,冒口颈短薄宽,可以防止球铁卡块的冲砂、夹渣、变形和尺寸超差等铸造缺陷,提高球铁卡块铸件的致密度和表面品质.     

金属型球铁磨球非平衡凝固特性的研究

探索了金属型球铁磨球非平衡结晶过程，并就磨球的非平衡凝固特性进行了较深入的分析研究。过共晶球铁凝固时出现非平衡奥氏体；亚共晶球铁出现晕圈铁素体和非平衡渗碳体相；在柱状晶与等轴晶过渡区中存在着偏聚物。为改善球铁磨球的显微组织及性能，球铁成分应控制在共晶或稍过共晶处。     

大型高铅青铜套的铸造

详述采用金属模覆砂和覆砂冷铁芯,上雨淋浇注等新工艺,铸造ZCuPb15Sn7高铅青铜套的过程。经生产实践验证高铅青铜铸件完全达到国外同类产品质量要求。     

空调压缩机D型石墨铸铁缸体的生产

采用水冷金属型铸造，并加入合金元素增大铁液过冷倾向，获得D型石墨铸铁，并用以生产空调器压缩机缸体，其金相组织和性能均达到技术要求。     

Review of current research and application of ductile cast iron quality monitoring technologies in Chinese foundry industry

There is a long history of studying and making use of ductile cast iron in China.Over the years,the foundrymen in China have carried out a lot of valuable research and development work for measuring parameters and controlling the quality in ductile cast iron production.Many methods,such as rapid metallographic phase,thermal analysis,eutectic expansion ratio,surface tension measurement,melt electrical resistivity,oxygen and sulfur activity measurement,ultrasonic measurement and sound frequency measurement,have been used and have played important roles in Chinese casting production in the past.These methods can be generally classified as liquid testing and solid testing according to the sample state.Based on the analysis of the present situation of these methods applied in the Chinese metal casting industry,the authors consider that there are two difficult technical problems to be currently solved in monitoring ductile iron quality.One is to seek an effective method for quickly evaluating the nodularizing result through on-the-spot sample analysis before the liquid iron is poured into the mould.The other is to find a nondestructive method for accurately identifying casting quality before castings are delivered.     

均衡凝固理论在铁模覆砂铸造大型空心球墨铸铁曲轴上的应用

介绍了铁模覆砂铸造大型空心球铁曲轴的工艺。采取平做、平浇、平冷和复合运用微量合金元素及多次孕育等技术措施，利用均衡凝固理论解决曲轴内部缩松，获得合格曲轴铸件，并得到铸态珠光体组织。     

拉速液位与结晶器出钢温度的关系研究

结晶器液位和铸坯拉速可直接影响结晶器内钢液温度.本文基于数值模拟和钢液凝固机理,建立起结晶器内钢液液位和铸坯拉速对其出钢口处钢液截面平均温度和坯壳温度的制约关系.仿真结果表明,所建立的关系模型能够反映结晶器出钢口处坯壳表面温度的动态变化,及间接地预知坯壳厚度目的.