一、序言随着石油化工的发展,乙烯装置趋于高收率、大型化,而裂解炉的操作温度向着高温方向发展。由于操作温度的提高,耐热铸钢辐射炉管的渗碳破坏已成为炉管的主要破坏形式。辐射炉管内部流体中的碳氢化合物和水蒸汽在高温条件下使炉管内壁形成硬度高、脆性大的渗碳层。因为渗碳层的机械性质和物理性质(热膨胀系数和导热系数)与母材不同,所以在经常的开、停车所造成的冷热循环过程中,辐射炉管反复承受拉、压热 First, the preface With the development of petrochemical industry, ethylene plant tends to high yield, large scale, and cracking furnace operating temperature towards high temperature direction. Due to the increase of operating temperature, the carburizing failure of heat-resistant cast steel radiant tube has become the main failure mode of the tube. Hydrocarbons and water vapor in the fluid inside the radiant tube make the inner wall of the tube form a carburized layer with high hardness and large brittleness under high temperature conditions. Because of the carburizing layer of the mechanical properties and physical properties (thermal expansion coefficient and thermal conductivity) is different from the base metal, so in the regular open, parking caused by the cooling cycle, the radiation tube repeatedly withstand pull, autoclave