厚大断面球墨铸铁件的生产

本文介绍了塑料机械和轧辊冷型用厚大断面球铁件生产的技术、工艺措施。     

稀土在大断面球铁件中的应用

铈组轻稀土对大断面球铁组织影响的模拟试验表明,铈组稀土合金完全可作为大断面球铁的有效球化剂而独立使用。铈无论作为球化剂或表面涂料都有利于消除碎块状石墨。在无微量干扰元素存在的纯净原材料中加入铈无损于大断面球铁组织。     

大断面型材生产特点

随着经济的发展,各行各业对铝型材的需求量越来越大,其中大断面型材的增长速度尤为韧带。着重谈了大断面型材的生产特点,设备配置、工艺要求等。     

日本大断面铝合金挤压型材生产技术

才窿日本轻金属挤压开发株式会社（ＫＯＫ）、日轻金蒲原挤压厂、神钢长的挤压厂以及宇部兴产株式会社挤压机制造厂和高取制模中心等工厂，在参阅了大量的文献资料后，对日本大断面铝合金挤压型材技术的发展概况、工艺装备水平、生产工艺特点等进行了较全面的介绍和分析，可供我国发展大断面铝合金挤压型材生产时作参考。     

离心球墨铸铁管的应用与生产

离心球墨铸铁管综合性能优良、施工维修方便，社会效益和经济效益显著，在世界各国尤其是经济发达国家得到广泛应用和发展，我国也在使用推广。例如，1991年，北京市密云水库引水工程就采用了日本久保田公司生产的DN2600mm大口径离心球墨铸铁管，北京市自来水公司也规定口径在300mm以上的铸铁管必须采用球墨铸铁管。我国自80年代以来，     

冲天炉生产高强度球墨铸铁轧辊研究

本文以生产实践介绍高强度球墨铸铁轧辊的生产工艺控制要点,展望应用前景。     

加快发展我国球墨铸铁管生产

球墨铸铁管具有与钢管接近的机械性能,使用寿命为钢管的2～4倍,其重量比普通铸铁管轻1/3,是埋入地下的最佳管材。球墨铸铁管在经济发达国家已基本上取代了普通铸铁管。我国近几年才建成四个球墨铸铁管车间,产量约为全国需量的10％左右。加快球墨铸铁管的生产发展,将会给城市、农业、工业建设带来显著经济效益。利用小高炉铁水生产球墨铸铁管,既节省能源,又为小高炉的产品延伸创出一条路。     

大断面铸态贝氏体球墨铸铁轧辊的试制

本文简述了直径大于４００ｍｍ铸态贝氏体球墨铸铁轧辊的试制过程，包括试制条件、试制工艺及试制品的性能分析。轧辊先后在６５０ｍｍ轧机上用于试轧厚８￣１３．６ｍｍ、宽２４０ｍｍ的扁钢。结果表明，其使用寿命为原铬钼球墨铸铁无限冷硬轧辊的１．５倍。     

DN800mm球墨铸铁管的生产

DN800mm管退火后存在延伸率低,合格率低的问题,经分析,退火炉轧道变形、铸态管本身椭圆及加热时间不够等是导致管子变形的主要原因。为此,高速铁水化学成分和浇注工艺参数,对退火炉炉底及轧道进行改造,并采用“高温快速”的退火工艺,从而提高了管子的圆整度和生产效率,退火合格率达到了100％。     

贝氏体球铁耐磨管生产工艺探讨

研究了硅锰合金化贝氏体耐磨管的成型工艺,讨论了贝氏体球铁管的化学成分、组织和性能等指标,研究表明:试验成分的贝氏体耐磨管成型性能良好,热处理工艺简单,硬度高,韧性好,成本低,实用经济效益显著,为贝氏体耐磨球铁管的应用开辟了广阔的市场前景。     

φ530mm轧机球墨铸铁梅花套管生产工艺控制

用中频感应电炉熔化Z14生铁，获得化学成分和温度比较稳定的原铁液，按适当比例加入球化剂和孕育剂，进行球化处理和孕育处理，可稳定地生产出φ530mm轧机用球墨铸铁梅花套管。     

奥氏体-贝氏体球墨铸铁断裂的微观过程及强韧化机理

用扫描电子显微镜及微拉伸台对奥氏体－贝氏体球墨铸铁裂纹萌生，扩展的微观过程进行了跟踪观察。结果发现：受拉时微裂纹首先在石墨－基体界面上萌生，并沿界面扩展，基体中的裂纹多数是沿贝氏体铁素体－奥氏体界面扩展，不同取向的基体组织可使裂纹偏转或分叉，主裂纹扩展过程中前方始终存在石墨－基体界面的开裂。此外，还根据实验结果进一步分析了奥氏体－贝氏体球墨铸铁的强韧化机理。     

Nucleation of Bainite in Bainite Ductile Cast Iron

The bainite ductile cast iron with given comppasition was quenched to get bainite strueture. The nucleating position of bainite and the distrihution of alloying elements in the matrix were measured. The results show thai the bainite nucleates at the interface between graphite and austenite during quenching. Based on the experimental results and thermodynamics, the nucleating tnechanism of bainite in ductile iron was analyzed.     

奥氏体-贝氏体球墨铸铁中石墨与基体界面的疲劳强度

采用系统分析的方法，通过3点弯曲疲劳实验，跟踪监测了奥氏体-贝氏体球墨铸铁试样的疲劳损伤过程。实验结果表明，奥氏体-贝氏体球墨铸铁中石墨球与基体组织界面有一定的疲劳强度；在不同的疲劳载荷作用下，该处疲劳开裂的时间和程度存在差异，并对疲劳裂纹的萌生和扩展有不同的影响。     

高延伸率球墨铸铁QT400-18材质试制

运用冲天炉熔炼试制QT400-18球墨铸铁,作为锌锭模的材质,提高锌锭模使用寿命。     

Mechanical Property Stability of Cu-Mo-Ni Alloyed Austempered Ductile Iron

The aim of present work is to investigate the influencing factors on mechanical property stability of Cu-Mo-Ni alloyed austempered ductile iron （ADI）. The results show that after austenitized at 900℃ for 2 h followed by austempered at 370℃for another 2 h, the mechanical property of the alloyed ADI can reach the Germanite GGG-100 standard, i.e. σb≮1000 MPa,δ≮5%, at 95% confidence level. And the satisfactory mechanical properties were obtained when the alloyed ADI was austenitized at 850℃ to 1 000 ℃ for 1-4 h, and austempered at 355℃ to 400℃ for another 1 h to 4 h. The microstructures, including nodule number, white bright zone content （martensite-containing interdendritic segregation zone） and retained austenite content, can significantly influence the mechanical properties of the ADI. In order to obtain the good combinations of strength and ductility, the volume fraction of white bright zone should he less than 5%, and the retained austenite contents maintain hetween 30 % and 40%. The application of inoculation techniques to increase graphite nodule number can effectively reduce the white bright zone content in the structure.     

Processing Maps for Use in Hot Working of Ductile Iron

  The hot deformation characteristics of ductile iron are studied in the temperature range of 973 to 1273K and strain rate range of 0001 to 1 s-1 by using hot compression tests. Processing maps for hot working are developed on the basis of the variations of efficiency of power dissipation with temperature and strain rate. The results reveal that the flow stress of ductile iron is sensitive to strain rate. In the processing map under strain of 07, a domain is centered at 1273 K and 1 s-1, and the maximum efficiency is more than 36%. According to the maps, the zone with the temperature range of 1173 to 1273 K and strain rate range of 01 to 1 s-1 may be considered as the optimum region for hot working.     

Very High Cycle Fatigue of Two Ductile Iron Grades

Two ductile iron grades, EN‐GJS‐600‐3 a ferritic–pearlitic grade, and EN‐GJS‐600‐10 a silicon strengthened ferritic nodular iron grade, are studied in the very high cycle fatigue range using a 20 kHz ultrasonic test equipment. Fatigue strengths and SN‐curves are achieved, and fracture surfaces and microstructures are investigated. The ferritic grade with higher ductility displays a lower fatigue strength at 10⁸ load cycles than the ferritic–pearlitic grade, 142 and 167 MPa, respectively. Examination of fracture surfaces shows that fatigue failures are controlled by micropores in both of the ductile iron grades, while the graphite nodule distributions do not seem to influence the difference in fatigue strengths. Prediction of the fatigue strengths, using a model for ductile iron proposed by Endo and Yanase, indicates a large potential for improvement in particular for the ferritic grade.