Development of wear resistant carbidic austempered ductile iron (CADI)
Development of wear resistant carbidic austempered ductile iron (CADI)
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DOI：
10.1016/j.wear.2007.08.013
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发表时间：
2008-06
期刊：
影响因子：
5
通讯作者：
S. Laino;J. Sikora;R. Dommarco
中科院分区：
文献类型：
--
作者：
S. Laino;J. Sikora;R. Dommarco
铁的耐磨性可以通过在基体中加入额外的相来改善，通常是碳化物。然而，耐磨性的改善通常伴随着冲击韧性的降低。本工作的目的是研究的方法，以获得一个控制的碳化物析出的球墨铸铁，随后等温淬火，获得所谓的碳化物等温淬火球墨铸铁（CADI）。由于基体的特殊特性，这种材料有望提供高耐磨性，但仍保持比其他强化铁更高的冲击韧性。一个板模型与铜激冷允许评估两者，高冷却速率的影响和合金元素对碳化物析出的效果。为了评估铬含量在1 - 2.5%范围内的影响，使用了四种具有接近共晶组成的当量碳的不同合金。对材料进行了详细的显微组织表征，特别研究了碳化物含量和成分，以及它们在热处理过程中的稳定性。通过在ASTM G 65标准下测试来评价耐磨耗性，获得相对于作为参考材料的常规ADI样品在1.02和1.95之间的相对耐磨耗性值。冲击韧性从ADI的约138- 101 J下降到CADI的约26- 7 J。
The abrasion wear resistance of irons may be improved by the incorporation of an extra phase to the matrix, typically consistent of carbides. Nevertheless, the improvement in wear resistance is generally accompanied by a decrease in the impact toughness. The aim of this work is to study the methodology to obtain a controlled precipitation of carbides in a ductile cast iron that is subsequently austempered, obtaining the so-called carbidic austempered ductile iron (CADI). This material is expected to offer high abrasion resistance but still retaining higher impact toughness than other reinforced irons, thanks to the particular characteristics of the matrix. A plate model with a copper chill allowed to evaluate both, the influence of a high cooling rate and the effect of alloying elements on carbide precipitation. Four different alloys with equivalent carbon close to the eutectic composition were used in order to evaluate the effect of chromium contents ranging from 1 to 2.5%. A detailed microstructural characterisation of the material was made, studying particularly carbide content and composition, besides their stability during the heat treatment. The abrasion wear resistance was evaluated by testing under the ASTM G 65 standard, obtaining relative wear resistance values ranging between 1.02 and 1.95 with respect to conventional ADI samples taken as reference material. The impact toughness decreased from about 138–101J for ADI to about 26–7J for CADI.