埋弧焊管导向弯曲变形测量与分析

对埋弧焊管的导向弯曲试验进行了理论分析,得到其应变公式,并计算了最大应变。将不同试样尺寸下钢材的断后伸长率,按Oliver公式换算到同一个标准条件下进行了比较。建立了弯曲应变判断公式来分析弯曲不合的基本原因。通过实际测量方法对弯曲试样的母材、热影响区和焊缝的应变进行了测量和分析,认为焊接接头的塑性一般足以满足导向弯曲试验要求。通过分析弯曲不合钢管酸洗样的显微照片,认为焊趾微裂纹是弯曲不合的主要原因。

Measurement and Analysis on SAW Pipe Guided Bend Test

In this article, the theoretical analysis of SAW pipe guided bend test was carried out, its strain formula was obtained, and the maximum strain was calculated. The percentage elongations after fracture of steel material under different sample size were compared, according to Oliver formula conversion to the same standard condition. It established a bend strain judging formula to find the basic reason of bend failure. By the method of actual measurement, the strain on bend specimens of parent metal, heat affected zone and weld was measured and analyzed, the result showed that the plasticity of welded jointer enough to meet the requirements of guided bend test. Through analyzing the micrograph of pickling sample of bend disqualified pipe, it considers that the microcrack in weld toe is the main reason of the bend disqualified test.