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采用自主开发的抗拉强度690 MPa级埋弧焊丝对16.3 mm厚同等强度级别钢板进行了双面双丝埋弧焊接试验,研究了焊接接头的组织和性能。焊缝组织性能测试结果表明,先焊面焊缝由针状铁素体、粒状贝氏体、上贝氏体及少量M-A组元和晶界铁素体组成,而后焊面焊缝则由针状铁素体、多边形铁素体、上贝氏体及少量M-A组元组成;先焊面硬度值(247 HV5)高于后焊面(232 HV5)与先焊面存在的粒状贝氏体组织有关;先焊面和后焊面的-20℃小试样冲击吸收能量分别为106 J和119 J,先焊面较低的冲击吸收能量与其较低含量的针状铁素体及粒状贝氏体的存在有关。全焊缝力学性能测试结果表明,焊缝的抗拉强度768 MPa,-20℃韧性≥165 J,断后伸长率为20%。热影响区组织性能测试结果表明,先焊面和后焊面的热影响区组织特征相似,其中粗晶区和临界再热粗晶区均由上贝氏体和粒状贝氏体组成,细晶区和临界区分别由多边形铁素体和M-A组元,以及上贝氏体、粒状贝氏体、多边形铁素体和M-A组元构成;上述各区域(粗晶区、临界再热粗晶区、细晶区和临界区)的硬度分别为236、232、229和234 HV5,其中粗晶区硬度值最高,其-20℃冲击吸收能量≥169 J。上述焊缝区和热影响区的组织和性能测试表明,焊接接头具有较好的强度与低温冲击韧性匹配。
The double-sided double-wire submerged arc welding test of 16.3 mm-thick steel plate of the same strength was carried out by self-developed tensile strength 690 MPa submerged arc welding wire. The microstructure and properties of welded joints were studied. The test results of the microstructure and properties of the weld show that the weld of the first weld consists of acicular ferrite, granular bainite, upper bainite, a small amount of MA and grain boundary ferrite. Ferrite, polygonal ferrite, upper bainite and a small amount of MA components. The first weld surface hardness value (247 HV5) is higher than that of the second weld surface (232 HV5) ; First welding surface and after welding the small specimen -20 ℃ impact energy absorption were 106 J and 119 J, the first welding surface of the lower impact energy absorption and its lower content of acicular ferrite and granular bainite The existence of the body. Test results of the mechanical properties of all welds show that the tensile strength of the weld is 768 MPa, the toughness of -20 ° C is ≥165 J, and the elongation at break is 20%. The microstructure and properties of the heat affected zone show that the HAZ of the first weld surface and the second weld surface have similar microstructure characteristics. The coarse grain region and the critical reheat coarse grain region consist of upper bainite and granular bainite, The zone and the critical zone are composed of polygonal ferrite and MA elements, as well as upper bainite, granular bainite, polygonal ferrite and MA elements, respectively; each of the above regions (coarse grain region, critical reheat coarse grain region , Fine grain region and critical region) were 236, 232, 229 and 234 HV5, respectively. The hardness value of the coarse grain region was the highest, and the impact absorption energy at -20 ℃ was more than or equal to 169%. The above-mentioned weld zone and heat-affected zone of the organization and performance tests show that the weld joint has good strength and low temperature impact toughness match.