Patent ID: 9394582
Filing Date: 2016-07-19
CPC Classification: C21D,C22C

Claim Text:
1. A method for producing a seamless steel pipe with an increased strength and improved toughness of the material by direct rapid cooling after a heat shaping, such that a cooling medium at an increased pressure is applied to the outside surface of the seamless pipe circumferentially for a length of more than 400 times the thickness of the seamless pipe wall within a period of at most 20 sec after the last shaping at a temperature greater than 700° C. but below 1050° C. in a continuous process, wherein the cooling medium is prevented from entering the interior of the seamless pipe, said cooling medium being applied in an amount which produces an equivalent cooling rate of greater than 1° C/sec of the seamless pipe wall over the length of the seamless pipe to a temperature in the range of 500° C. to 250° C. in rapid cooling, after which the pipe is cooled further in air to room temperature.