電子ビーム溶接の欠陥発生および防止に関する研究 Ｖ 厚鋼板の横向電子ビーム溶接法の検討

Abstract

Horizontal position electron beam welding of heavy section 0.170-steel, 21/4 Cr-I Mo low alloy steel and 18 Cr-8 Ni steel plates up to 100 mm in thickness was investigated using a 42 kW (60 kV) high vacuum type welding machine.Penetration characteristics and occurrence and prevention of welding defects were discussed comparing horizontal position welding with flat position welding.It was concluded that, I. Partial penetration(1) Penetration depths in horizontal position were 15 to 20 % deeper than in flat position.(2) Voids occurred, when the penetration depth in horizontal position exceeded 50 mm and no oscillation was applied to the beam.(3) Effects of focus position on tendency of occurrence of welding defects and bead shapes in horizontal position were smaller than in flat position.(4) Lack of molten metal seemed to cause voids in horizontal position welding.II. Full penetration(1) Occurrence of voids in horizontal position was influenced by value and fluctuation of penetration current, and oscillation conditions of the beam.(2) Beam oscillation (X direction, 100 Hz) was effective to prevent void formation in full and partial penetration welding.