Production process method of small-caliber cold-drawing seamless steel tube used for boiler

Abstract

The invention provides a production process method of a small-caliber cold-drawing seamless steel tube used for a boiler. The technological method including the steps of heating with an annular heater, punching by oblique rolling, tube-rolling by an automatic tube rolling mill, reducing a diameter by using a reducing mill through hot-rolling, cold-drawing and performing heat treatment is adopted. As high temperature of a steel tube is utilized to perform diameter reduction process on the steel tube, diameter reduction rate reaches to 25%, number of cycles of the cold-drawing of the steel tube is reduced, cold-drawing amount is respectively reduced by 30-70%, optimal production technology of the steel tube of a high-pressure boiler is created, energy consumption for steel tube production is reduced, and production efficiency is improved. According to the invention, a tube billet is obliquely placed in the annular heating furnace through a mechanical arm to lengthen the heating length, so that an overlong steel tube can be produced by using the lengthened tube billet. Under the condition of short-process production process the performance control method of the cold-drawing seamless steel tube is adopted by the boiler, the technologies such as small flow, multiple nozzles arranged at the side surfaces and the like are adopted by the heat treatment furnace; a computer fuzzy control technology is adopted by the heating furnace and the heat treatment furnace to control atmospheres inside the furnace; and the performances and organization of the produced cold-drawing boiler steel tubes are satisfied with standard requirements.

Description

technical field [0001] The invention relates to a production process for small-diameter cold-drawn seamless steel pipes for boilers, in particular to a production process for super-long and super-heavy steel pipes at low cost. Background technique [0002] In order to meet the supercritical and ultra-supercritical development requirements of power plant boilers and improve the processing performance of seamless steel pipes for boilers, the length of cold-drawn seamless steel pipes for small-diameter boilers has been developed to more than 12m, and the diameter and length of raw material tube blanks have increased. , the traditional production process mainly includes the following steps: piercing, automatic tube rolling, cold drawing and heat treatment. Due to the increase in the length of the finished steel tube, the diameter of the tube blank increases and the number of cold drawing passes increases. Therefore, the tube blank heating length of the original heating equipment ...

AI Technical Summary

Problems solved by technology

Generally, tube blanks close to the diameter of the finished product are used for production, but due to the limitation of rolling length, small tube blanks cannot meet the requirements of product unit weight

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