【摘要】 在 8 0℃和 2 .4MPa恒应力拉伸的试验条件下 ,参照ASTMF14 73 97标准 ,研究了国产燃气用PE80管材与其热板熔焊焊缝的慢速裂纹扩展 (SCG)行为。研究表明二者SCG过程的δ -t关系均为同样的阶梯上升形态 ,这一形态是裂纹尖端区域材料的蠕变钝化与蠕变损伤积累过程相互转换的宏观表现。就所得试验结果的平均趋势而言 ,与PE80管材本身性能的比较 ,其熔焊焊缝的SCG抗力相对较差更多还原

【Abstract】 Under the experimental condition of 80 ℃ and 2.4 MPa constant tensile stress, the behaviors of slow crack grow (SCG) of PE 80 fuel gas pipe produced in China and its hot-plate fusion weld are investigated referring to the Standard of ASTM F1473-97. Investigation shows that the relationships of δ-t for both processes of SCG are of the same step by step rising form, which is the macro-representation of conversion between the creep blunting and the creep damaging occurring 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 than that of PE 80 pipe itself.更多还原