中国低活化马氏体钢TIG焊焊接接头的高温蠕变性能分析

Analysis on creep properties of TIG welding joints of China low activation martensitic steel

文中在钨极氩弧焊条件下，在温度823K和180—260MPa应力水平下对CLAM钢焊接接头的蠕变性能进行了研究，作出蠕变曲线，建立数学模型分析预测蠕变变形机制．结果表明，CLAM钢TIG焊焊接接头表现出典型的三阶段蠕变过程；Or温度一定的情况下随着应力水平的提高，稳态蠕变速率增加，断裂时间变短．通过蠕变方程得到的稳态阶段焊接接头的应力因子n大于合金典型值3～7，其激活能Q约为436kJ／（mol·K），并且大于铁的自扩散激活能（300kJ／（mol·K）），显示为位错主要控制蠕变变形．

In this work,the creep properties of China Low Activation Martensitic( CLAM) steel TIG welding joint have been carried out in the temperature of 823 K and with the applied stress from 180 to 260 MPa. The creep curve and creepmechanism with mathematic model is analyzed. The results show that the TIG welding joints exhibited the typical three-stage creep curves; the minimum creep rate increasedat a constant temperature,the rupture time decreases with the stress increasing. The stress exponent n obtained by creep equation was higher than the typical values of 3 ~ 7,and the activation energy Q was about436 KJ / mol. K,which is also higher than the self diffusion energy of Fe( 300 KJ / mol·K) indicating a dislocation creep deformation mechanism.