Production method of large-caliber high-pressure boiler tube

Abstract

The invention provides a production method of a large-caliber high-pressure boiler tube, comprising the following steps: inspecting blank; saw cutting blanking; heating by an annular furnace; punching by a Mannesmann punching machine or punching by hydraulic pressure and punching by utilizing the Mannesmann punching machine; pre-punching a mandril; rolling by a pilger mill; carrying out hot-sawing on pilger heads; reheating by a walking beam furnace; externally descaling by high pressure water; sizing by a sizing mill; cooling by a cooling bed; carrying out thermal treatment; sampling; passing physical and chemical inspection; straightening; cutting head and end parts; carrying out manually initial check; polishing an inner surface and an outer surface or internally boring and externally raking; blowing soot; carrying out ultrasonic and eddy-current combination detection; manually rechecking; carrying out spectral inspection; measuring length and weighing; jet-printing; and finally packaging and warehousing. In the method, a steel billet is heated in the annular furnace, which comprises three processes of preheating, heating and soaking; and heating temperature and time in each process are rationally distributed to prevent heating unevenness and heating defects. During the tube rolling process, the feeding system of the pilger mill completes feeding release with the feeding quantity less than 0.5mm, thus achieving uniform and accurate feeding quantity in each rolling cycle.

Description

technical field

[0001] The invention relates to the field of manufacturing seamless steel pipes, in particular to a method for producing large-diameter high-pressure boiler pipes. Background technique

[0002] Large-diameter high-pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, air guide tubes, and main steam tubes for high-pressure and ultra-high pressure boilers. Large-diameter high-pressure boiler tubes are often used under high temperature and high pressure conditions. Under the action of high-temperature flue gas and water vapor, the steel tubes will be oxidized and corroded. The steel tubes are required to have high durable strength, high oxidation and corrosion resistance, and good organization stability.

[0003] At present, the main methods used in the production of large-diameter high-pressure boiler tubes in my country are: secondary piercing process, thermal expansion process, pipe jacking process and old-fashioned periodic...

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