大线能量焊接船板钢焊缝冲击断裂机理

Impact Fracture Mechanism of Large Linear Energy Welding Seam of Shipping Steel

对厚度分别为16、25、40 mm的EH36船板钢相应地用50、100、150 k J/cm的线能量进行了埋弧焊接试验,并制取焊缝区的冲击试样,在-40℃下进行了冲击试验,通过观察冲击断口的宏微观形貌研究焊接接头的冲击断裂机理。结果表明,三种板厚的船板钢焊缝中心的冲击吸收功均达到冲击要求;宏观形貌上,各焊缝中心试样的冲击断口均凹凸不平,剪切唇区域呈明显暗灰色,塑性变形量较大;微观形貌上,焊缝中心试样的断裂以塑性断裂为主,伴有少量的脆性断裂特征。

The submerged arc welding tests of EH36 shipping plates with thicknesses of 16, 25 and 40 mm were carried out by using linear energy of 50, 100 and 150 k J/cm respectively. The impact samples of the weld zone were prepared, and the impact tests were carried out at-40℃, and the impact fracture mechanism of the welded joints was investigated by observing the macroscopic and microscopic morphologies of impact fracture. The results show that the impact absorbing energy of weld center of the three kinds of steel plate reaches the impact requirements. From the prospect of macroscopic morphology, the impact fracture of the weld center specimens is uneven, the shear lip region is dark grey, and the plastic deformation is large.From the prospect of microscopic morphology, the fracture of the weld center specimen is mainly plastic fracture,accompanied by a small amount of brittle fracture.