Welding Heat Input Limit of Rolled Steels for Building Structures Based on Simulated HAZ Tests(Mechanics, Strength & Structure Design)
Welding Heat Input Limit of Rolled Steels for Building Structures Based on Simulated HAZ Tests(Mechanics, Strength & Structure Design)
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基于模拟热影响区试验的建筑结构用轧制钢材焊接热输入极限（力学、强度）
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
H. Kamura
中科院分区：
文献类型：
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作者：
Y. Sakino;K. Horikawa;H. Kamura
在坂神淡路大地震中，钢结构框架梁柱节点普遍发生屈服脆性断裂。在影响一般屈服脆性断裂的诸多因素中，断裂韧性的影响最为显著。一些研究明确了母材和焊缝金属所需的韧性，但没有提出一般值。此外，由于低碳钢的焊接热影响区（HAZ）韧性下降，因此，关注焊接热影响区韧性下降也很重要。本文研究了“建筑结构用轧制钢”模拟热影响区的韧性与其焊接线能量极限之间的关系，试图为热影响区提供所需的韧性。讨论了焊接热输入后硬度和韧性的提高与显微组织变化的关系。主要研究结果如下。1)与SN490B相比，SN400B可以在更高的热输入下保持其韧性。2)在相同的热输入下，该钢种比其他钢种硬度提高，吸收的能量小，热输入极限也小。3)对于某些要求的韧性值，分别提出了SN400B和SN490B的焊接热输入限值。
In The Great Hanshin-Awaji Earthquake, the general yield brittle fractures were observed in beam-column connections of steel building frames. Among many influencing factors which affect the general yield brittle fracture, it can be considered that fracture toughness has substantial effects. Some studies are making clear the required toughness for the base metal and the weld metal, but general values are not proposed. Moreover, it seems that it is also important to pay attention to the toughness decrease in the weld heat affected zone (weld HAZ), because the toughness decrease occurrs in the HAZs of mild steel. In this paper, the relationship between toughness of simulated HAZs of “the rolled steels for building structures (SN)” and the weld heat-input limit of the SN steel are investigated, in an attempt to provide the required toughness for HAZs. The relationships between the increase of the hardness value and toughness, and changes of microstructure after weld heat-input are also discussed. The main results are summarized as follows. 1) The SN400B can keep its toughness at higher heat-inputs compare to the SN490Bs. 2) The steel grade, which becomes harder than other steel grades at the same heat-input, has smaller absorbed energy and smaller limit of heat-input. 3) The weld heat-input limit of the SN400B and the SN490B are proposed separately for some required toughness values.