等温淬火球墨铸铁(ADI)的低温性能与环境脆性

Low Temperature Properties and Environmental Brittleness of Austempered Ductile Iron

论述了ADI的低温冲击韧度、断裂韧度及环境脆化问题。ADI的冲击韧度随温度下降而降低,但在-40℃条件下仍保持室温冲击韧度的约70%;ADI的断裂韧度随温度下降而降低,在-60℃时具有大约室温断裂韧度的60%~80%。在有水或氢存在的环境下,当受力超过屈服极限时,ADI材料有明显的脆化现象,通常ADI零件的工作应力远小于材料的屈服强度,由水脆化引起的ADI零件失效非常少见。

This paper discussed the low temperature impact toughness,fracture toughness and environmental brittleness of austempered ductile iron(ADI).The impact toughness of the ADI decreases with the decreasing of temperature,but it remains about 70%of room temperature impact toughness at-40℃.The fracture toughness of the ADI decreases with temperature and is 60%-80%of room temperature fracture toughness at-60℃.In the presence of water or hydrogen,when the force exceeds the yield strength,the ADI has obvious brittleness.However,usually the working stress of the ADI parts is much less than the yield strength of the material,and the failure of the ADI parts caused by the water brittleness is very rare.