著者

前中 浩 佐久間 正明 松岡 一祥

出版者

社団法人溶接学会

雑誌

溶接学会論文集 : quarterly journal of the Japan Welding Society (ISSN:02884771)

巻号頁・発行日

vol.4, no.1, pp.95-101, 1986-02-05

---

The stress relief phenomena in pre-loading on butt welded plates and the changes of material properties owing to the pre-loading were investigated theoretically and experimentally. A over-matching welded joint composed of a 50 kgf/mm^2 class weld metal by automatic CO_2 welding and a mild steel of 16 mm thickness was tested. The strain distributions measured by strain gages showed the same tendency to those calculated by FEM, under pre-loadings in directions perpendicular and parallel to the weld line. The perpendicular loading was superior to the parallel loading in terms of reducing the plastic strains caused of the stress releaving. Strain aging embrittlement of weld metal, HAZ and base metal obtained by 2 mm V notched Charpy test was quite proportional to prestrain, and significant difference among them could not be found. The equations for estimation of the brittle fracture initiation temperature were checked. The rise in the temperature caused by the pre-loading was less than that due to the weld residual stress. It was concluded that the effective pre-loading method recommended in the present paper was sufficiently safe.

著者

前中 浩 佐久間 正明 松岡 一祥

出版者

JAPAN WELDING SOCIETY

雑誌

溶接学会論文集 (ISSN:02884771)

巻号頁・発行日

vol.4, no.1, pp.95-101, 1986

---

The stress relief phenomena in pre-loading on butt welded plates and the changes of material properties owing to the pre-loading were investigated theoretically and experimentally. A over-matching welded joint composed of a 50kgf/mm<SUP>2</SUP> class weld metal by automatic CO<SUB>2</SUB> welding and a mild steel of 16 mm thickness was tested.<BR>The strain distributions measured by strain gages showed the same tendency to those calculated by FEM, under pre-loadings in directions perpendicular and parallel to the weld line. The perpendicular loading was superior to the parallel loading in terms of reducing the plastic strains caused of the stress releaving.<BR>Strain aging embrittlement of weld metal, HAZ and base metal obtained by 2 mm V notched Charpy test was quite proportional to prestrain, and significant difference among them could not be found. The equations for estimation of the brittle fracture initiation temperature were checked. The rise in the temperature caused by the pre-loading was less than that due to the weld residual stress. It was concluded that the effective pre-loading method recommended in the present paper was sufficiently safe.

著者

太田 昭彦 渡辺 修 松岡 一祥 志賀 千晃 西島 敏 前田 芳夫 鈴木 直之 久保 高宏

出版者

社団法人溶接学会

雑誌

溶接学会論文集 : quarterly journal of the Japan Welding Society (ISSN:02884771)

巻号頁・発行日

vol.18, no.1, pp.141-145, 2000-02-05

参考文献数

18

被引用文献数

22

---

The fatigue strength of developed box welds was improved about two times of the conventional box welds. The improved welds used the low transformation temperature welding material which contains 10% Cr and 10% Ni. The expansion of the developed welding material was 0.55% due to the transformation from austenite to martensite. This expansion induced the compressive residual stress around welds. On low stress range condition, the stress ratio effect by this compressive residual stress avoids the fatigue crack initiation at the weld toe. On high stress range condition, the fatigue crack initiated from weld toe and the fretting was observed on the fractured surface. While in the conventional welds, no trace of fretting was observed.