To provide a method for sufficiently suppressing the variation of quality in the longitudinal direction of a product since the material temperature (working temperature), when performing stretch rolling while restraining the inner surface of a hollow tube stock with a plug, becomes uneven in the longitudinal direction.
In a method of manufacturing a seamless steel tube by which, after heating a material 1 to be worked, the original shape of which is a round billet, it is made into the hollow tube stock by performing piercing, successively, elongating is performed while restraining the inner surface of the hollow tube stock with the plug, next, sizing is performed after reheating and, next, the hollow tube stock is made into the seamless steel tube by cooling it, the material to be worked is heated so that the temperature of the top in the longitudinal direction of the material to be worked just before the elongating becomes a temperature higher than that of the rear end by 30-400°C, before the elongating of the material to be worked.
KATSUMURA TATSURO
ISHIKAWA KAZUTOSHI
| JPS61108409A | 1986-05-27 | |||
| JPH08117817A | 1996-05-14 | |||
| JP2000246310A | 2000-09-12 |
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