多因素耦合下Cr35Ni45Nb钢乙烯裂解炉管损伤数值模拟

Numerical Simulation of Damage for Cr35Ni45Nb Steel Ethylene Cracking Furnace Tube at Action of Coupled Multiple Factors

基于连续损伤力学理论,利用FORTRAN语言开发了多因素耦合下材料损伤发展的ABAQUS用户子程序,模拟了1050℃温度下,蠕变-渗碳耦合作用的Cr35Ni45Nb钢损伤发展过程。结果表明:承受单一蠕变损伤的炉管外壁最先失效,而承受蠕变-渗碳耦合作用下的炉管内壁最先开裂。单一蠕变因素下Cr35Ni45Nb钢的内壁Von-mises应力和最大主应力随着服役时间的延长出现先降低后增长的趋势。外壁的Von-mises值和最大主应力随着服役时间的延长而增大,从而导致炉管外壁的损伤发展速率高于内壁。蠕变-渗碳耦合作用下Cr35Ni45Nb钢的内壁Von-mises应力和最大主应力随着服役时间的延长而降低,而外壁则相反。

Based on the continuum damage mechanics（CDM）,a user subroutine of ABAQUS coded by FORTRAN was developed for simulating the damage process of Cr35Ni45Nb steel ethylene cracking furnace tube at action of coupled creep-carburization under 1050℃.The results showed that the inner surface of tube generated micro-cracks firstly at action of coupled creep-carburization.However,the rupture initiated from the outer surface at action of single creep.The Von-mises stress and maximum principal stress along the inner surface decreased initially and then increased with time at the action of single creep.And the Von-mises stress and maximum principal stress along the outer surface increased with time,which caused the damage rate of outer surface to be higher than that of inner surface.The Von-mises stress and maximum principal stress along the inner surface decreased with time at action of coupled creep-carburization,which was contrary to the outer surface.