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八字裂纹模拟容器静压爆破和低周疲劳试验研究针对受内压的大型容器常在电渣焊缝中存在枝晶状“八”字裂纹,为探讨糟斜裂纹的圆筒容器极限载荷计算方法及斜裂纹在低周疲劳载荷下亚临界扩展规律,采用27个带有18MnMoNb钢电渣焊缝、手工补焊焊缝及母材的模拟容器,热处理状态为正火—回火、调质和调质后手工补焊(在焊缝及母材上预制与筒壳切向夹角为0°、15°、30°、45°、60°、90°的人工贯穿裂纹),进行了静压爆破和低周疲劳试验。试验表明,斜裂纹一经开裂扩展就改变方向并沿着此方向基本呈直线扩展,直到疲劳失稳。对这种裂纹,本文提出两种简化计算方法(直线法和投影法),而且
Study on Static Pressure Blasting and Low-cycle Fatigue Test of Crack Simulator For dendritic “eight” crack in large-scale container subject to internal pressure, in order to investigate the method of calculating the ultimate load of cylindrical container with bad crack, And subcritical propagation of oblique crack under low cycle fatigue loading, 27 simulated vessels with 18MnMoNb steel electroslag welds, hand welding welds and base metal were used. The heat treatment conditions were normalizing-tempering, quenching and tempering After the quenching and tempering, the manual welding (manual penetration through the weld seam and the preform and tangential angle of the shell of the welding seam and the shell is 0 °, 15 °, 30 °, 45 °, 60 ° and 90 °) Blasting and low cycle fatigue test. Experiments show that once the crack propagates, the oblique crack changes direction and expands linearly in this direction until the fatigue failure. For this kind of crack, this paper presents two simplified calculation methods (straight line method and projection method), and