20×10~4m^3油罐厚钢板焊接裂纹敏感性试验

Welding crack sensitivity test on thick steel plate of 20×10~4 m^3 oil tank

油罐罐体由钢板焊接而成,焊缝是油罐的薄弱部位,随着钢板厚度的增加,其焊接裂纹敏感性增强。20×104m3油罐底圈壁板采用的钢板厚度为44mm,其焊接性能目前尚无工程实例验证,因此,对其焊接裂纹敏感性开展试验研究,以确定合理的焊接工艺参数。斜Y型坡口裂纹试验结果表明:母材和过热区金相组织均为粒状贝氏体,焊缝组织为"先共析铁素体+贝氏体+针状铁素体",组织未见异常;对于JFE-HITEN610E钢板,采用LB-62UL焊条焊接,焊缝在室温14℃、预热50℃和100℃条件下均表现出较好的抗裂性能。对接接头刚性拘束焊接裂纹试验结果表明:母材和过热区金相组织均为粒状贝氏体,焊缝金相组织为贝氏体,组织未见异常;JFE-HITEN610E钢板和配套的US49/US62A(直径3.2mm)焊丝+MF33H焊剂,焊缝在室温14℃和预热50℃条件下均表现出较好的抗裂性能。

Oil tank is welded with steel plates,of which the weld joint is the weakest part of the tank.With the increase of steel plate thickness,welding crack sensitivity is enhanced.20×104 m3 tank foundation ring wallboard is made of 44 mm thick steel plates,of which welding performance is not verified by engineering examples.Therefore,experimental research is carried out for welding crack sensitivity to determine reasonable welding parameters.Oblique Y groove cracking test results show that the metallographic structures of base metal and overheated zone are granular bainite and weld joint structure is 'proeutectoid ferrite + bainite + acicular ferrite' without abnormal conditions.JFE-HITEN610E steel plates use the LB-62UL electrode for welding and the weld joints have better crack resistance at room temperature 14 ℃ and under warm-up conditions of 50 ℃ and 100 ℃.Butt joint rigidity restraint welding crack test results show that metallographic structures of base metal and overheated zone are granular bainite,and metallographic structure of weld joint is bainite without abnormal conditions.JFE-HITEN610E steel plates use supporting US49/US62A(diameter of 3.2 mm) welding wire + MF33H flux,of which weld joints have the better crack resistance at room temperature 14 ℃ and under warm-up conditions of 50 ℃.