通过等温淬火获得含碳化物等温淬火球墨铸铁（carbidic austempered ductile iron，简称CADI），并分别在中性、酸性和碱性腐蚀介质中进行腐蚀磨损实验，研究淬火温度对CADI在不同腐蚀介质中耐腐蚀磨损特性的影响，并与低铬铸铁进行对比。结果表明：在酸性和碱性介质中，CADI 的质量磨损随等温淬火温度升高先增加，然后再减少；在中性介质中，CADI 的质量磨损随等温淬火温度升高而逐渐增加；CADI 在酸性介质中的耐腐蚀磨损性能相对较差；CADI在不同pH值溶液中的耐磨损性能均优于低铬铸铁，是一种优良的耐腐蚀磨损材料。

In order to study the effects of austempered temperature on corrosive wear behaviors of carbidic austempered ductile iron (CADI), the CADI was prepared, and the wear corrosion resistance test was conducted in acid medium, neutral medium and alkaline medium, respectively. The results show that in acid medium and alkaline medium, the mass loss of CADI first increased and then decreased with increasing austempered temperature. But in neutral medium, the mass loss of CADI increased gradually with increasing austempered temperature. The performance of corrosion wear resistance of CADI in acid medium is inferior to that in alkaline medium and neutral medium. While the performance of corrosion wear resistance of CADI is obviously superior to that of low chromium white cast iron under different pH values medium. Therefore, CADI is a material with good property of corrosion wear resistance.

研究了Mn和热处理工艺对中碳低合金耐磨铸钢组织和力学性能的影响。结果表明,实验钢的最佳奥氏体化温度为870℃,实验钢经不同温度淬火、低温回火后,钢的硬度变化并不显著,在46~54 HRC之间;w(Mn)1.5%时经870℃奥氏体化+等温淬火和200℃回火热处理,试验钢回火后的组织主要为回火马氏体,材料获得最佳的综合力学性能,是矿用挖掘机铲齿最好材质之一。

The influences of Mn and heat-treatment on microstructure and mechanical properties of medium-carbon-low-alloy wear-resistant cast steel were investigated. The results show that the best quenching temperature is 870 ℃,the hardness is not significantly changed (46~54 HRC)through different quenching and tempering temperature. The optimal impact toughness of the tested steel can be obtaind by quenching at 870℃and tempering at 200℃. Microstructure finds that steel after tempering main matrix of tempered martensite.

对35CrMo钢等多种材料奥氏体化后进行贝氏体等温淬火,得到少量贝氏体+马氏体+残留奥氏体的整合组织。应用JEM-2100透射电镜和QUANTA-400环扫电镜等设备观察了贝氏体组织的形貌和亚结构。综合分析了贝氏体相变的特征。研究表明,过冷奥氏体随着温度的降低具有转变贯序,贝氏体相变在组织形貌、亚结构方面具有过渡性。贝氏体相变动力学具有交叉性、重叠性、变温性和等温性的过渡性特征。贝氏体相变中铁原子和置换原子以非协同热激活跃迁方式位移,表明贝氏体形核长大具有过渡性。

35 CrMo steel and other materials were austenitized and quenched isothermally in the bainite transformation zone,with the result that a integrated microstructure consisting of a small amount of bainite, martensite and retained austenite was developed.The morphology and substructure of the bainite were observed by JEM-2100 transmission electron microscope and QUANTA-400 environmental scanning electron microscope.The characteristics of bainite transformation were comprehensively analyzed.The results show that with the decrease in the temperature,the supercooled austenite exhibits transformation sequence,and the bainite transformation has transient characteristics in structure morphology and substructure.The bainite transformation dynamics has transient characteristics,such as intersecting,overlapping,variable- temperature and isothermal characteristics.The iron and replacement atoms will shift through the medium of non-synergic thermal activation transition during the bainite t