大壁厚高钢级管线钢DWTT断口分析

摘要

Drop-weight tear test specimens with various types of notch and various thickness of heavy wall thickness pipeline steel were tested and fracture appearances were analyzed. The result indicated that the definition about invalid specimens in API RP 5L3 is already inapplicable for thick wall and high-grade pipeline steel; the abnormal fracture appearances likely appear in DWTT pressed notch specimen. So it is suggest that chevron notch and entire wall thickness specimen are used in test. For thick wall and high-grade pipeline steel, the fracture appearance easily appears lamination in DWTT no matter type of notch.%对不同缺口形式和不同厚度的大壁厚高钢级管线钢试样进行了落锤撕裂试验,并对断口形貌进行了研究.结果表明:API RP 5L3对无效试样的定义已经不适用于大壁厚高钢级管线钢;大壁厚高钢级管线钢的DWTT压制缺口试样出现异常断口的几率较大.建议在试验时尽量采用人字形缺口的全壁厚试样;对于大壁厚高钢级管线钢,不管何种缺口形式的落锤撕裂试样,其断口都容易出现分离现象.