| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of gas-pressure welding using a open butt method, by which a pre-processing is unnecessary, a pressure welding can afford to be surely performed, a reliable joint is made possible, and a safe work is assured. SOLUTION: In the method of gas-pressure welding, the butt faces of works W are spaced and set on pressure welding equipment, ring burners 1, 2, and 3 are ignited, both butted faces are simultaneously heated by oxygen and a strongly reducing gas while gas-sealed by a strongly reducing flame, and a heated zone is heated by oxygen and the non-reducing gas. The butted faces are pressurized at a time when the heated zone is turned red and both butted faces are beginning to be melted, and brought into tight contact with each other until the upper pressure limit is reached, than the ring burner 1 for the strongly reducing gas is turned off and the heating work is continued with the ring burners 2 and 3 for the non-reducing gas, and a knot is formed at the time when the pressurizing force reaches the lower limit pressure.
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