Comparative testing for crack resistance (fracture toughness) of weld metal specimens of a low-carbon steel welded joint in the as-supplied condition and after high-temperature exposure at a temperature of 1200 °C for 3.7 hours is conducted. A welded joint is obtained by automatic argon-arc welding with a consumable electrode in a hot-rolled 22K-type steel sheet of 60 mm thick using welding wire grade SV-08G2S. Tests for static crack resistance of specimens with a stress concentrator are carried out according to a three-point bending scheme. One of the energy criteria of nonlinear fracture mechanics, critical J-integral [J/m²], which takes into account plastic deformation at a crack tip, is used as a crack resistance characteristic. It is shown that high-temperature exposure leads to an increase in crack resistance (the J-integral value increases by two times) as a result of phase recrystallization and improving the coarse-grained overheated weld structure.

对低碳钢焊接接头焊缝金属试件在供货状态下和在1200℃高温暴露3.7小时后进行抗裂性（断裂韧性）对比试验。采用自耗电极自动氩弧焊，使用等级 SV-08G2S 焊丝在 60 mm 厚的热轧 22K 型钢板上获得焊接接头。带有应力集中器的试样的静态抗裂性试验是根据三点弯曲方案进行的。非线性断裂力学的能量准则之一，临界J-积分[J/m² ]，其考虑了裂纹尖端处的塑性变形，被用作抗裂特性。结果表明，由于相再结晶，高温暴露导致抗裂性增加（J-积分值增加两倍）改善粗晶过热焊缝组织。