聚乙烯管材热熔焊缝SCG过程的特征量及其统计学评价

Under the experimental condition of 80℃ and 2.4MPa constant tensile stress, this paper investigates the behaviors of slow crack grow (SCG) of PE 80 fuel gas pipe and its hot-plate fusion weld, referring to the Standard of ASTM F1473-97. The investigation shows that the relationships of δ ~t for both processes of SCG are of the step by step rising form, which is the macro-representation of conversion between the creep blunting and the creep damaging occurred at the crack tip. Based on the average tendency offered by the SCG experimental results, it is confirmed that the resistance of fusion weld to SCG is lower compared with that of PE 80 pipe itself.