A new proposal of HAZ toughness evaluation method - Part 1: HAZ toughness of structural steel in multilayer and single-layer weld joints

作者：Furuya H^*; Aihara S; Morita K

来源：Welding Journal, 2007, 86(1): 1S-8S.

A huge earthquake experienced in Japan led to the establishment of a new guideline to prevent the brittle fracture of building structures in terms of design, construction, and material. For steel, it was suggested to have heat-affected zone (HAZ) toughness of more than 27 or 70 J in the Charpy impact test at 273 K. This paper relates an investigation into a HAZ toughness evaluation method for construction structural steels. The HAZ toughness was examined for both multi-layer and single-layer weld joints, and the characteristics of both methods were compared. The points below were the result.
The method with the multilayer weld joints showed relatively high toughness, and it has a possibility to provide data scatter depending on the welding deposition sequence and the notch sampling position. On the other hand, the method with the single-layer weld joints gave lower toughness. lt is less affected by the notch sampling position, and it reflects the effect of the carbon equivalent and the welding condition through a change in microstructure. Consequently, the HAZ toughness estimation using the single-layer weld joints has an advantage from the viewpoint of the lower bound toughness evaluation.

• 出版日期2007-1