Continuous casting process for boiler pipe steel resistant to sulphuric acid dew point corrosion

Abstract

The invention relates to a continuous casting process for boiler pipe steel resistant to sulphuric acid dew point corrosion. A full-protecting pouring mode is adopted during continuous casting. A long nozzle argon sealing protecting casting mode is adopted from a steel ladle to a tundish. An integrated built-in submersed nozzle protecting casting mode is adopted from the tundish to a crystallizer. Molten steel in the tundish uses molten steel covering agents. Continuous temperature measurement is carried out on the tundish. Full-automatic liquid surface detection is carried out on the liquid surface of the crystallizer in the continuous casting process. The continuous casting pulling rate is automatically controlled according to the superheat degree of the tundish. Automatic water distribution is carried out for the crystallizer and secondary cooling. The crystallizer uses special casting powder for the boiler pipe steel resistant to sulphuric acid dew point corrosion in the casting process. By means of the continuous casting process for the boiler pipe steel resistant to sulphuric acid dew point corrosion, the surface cracks of rolled metal can be largely reduced, and the flaw detection rate and yield are greatly increased.

Description

Technical field [0001] The invention involves a kind of casting process in the field of metallurgy. Specifically, it is a continuous casting process for sulfuric acid dew point corrosion. Background technique [0002] Boiler is a special equipment that cannot make a slightest error on safety issues, and the quality of the raw materials, especially steel, is crucial.The boiler is under the jurisdiction of the "Special Equipment Safety Supervision Regulations". The selection of suppression component materials in boiler manufacturing shall follow the "Steam Boile Safety Technical Supervision Regulations", "Hot Water Boiler Safety Technical Supervision Regulations" and "organic thermal carrier furnace safety technical supervisionThe requirements of the corresponding terms in the Regulations, Chapter 3 of the Steam Boiler Safety Technical Supervision Regulations stipulates the scope of the steel used for the steel used in the stress component of the boiler. Their applicable pressure, ...

AI Technical Summary

Problems solved by technology

Most of the boiler tube steels required by enterprises in metallurgy, electric power, petrochemical, waste-to-energy and other industrial fields are mainly supplied from abroad, but the supply period is long and the price is expensive, which seriously restricts the development of my country's power industry, or uses other materials Replacement, but it is easy to corrode, the maintenance cost is high in the later period, and the hidden danger of equipment safety is great, which affects the economic development speed of our country.

[0023] China started the trial production of sulfuric acid dew point corrosion-resistant boiler tube steel late, and adopted the continuous casting process to produce continuous casting billets of sulfuric acid dew point corrosion-resistant boiler tube steel. Cu and S elements are crack-sensitive elements, and the internal and external quality is unstable. It is mainly manifested in the existence of element segregation, excessive central cracks in low-magnification central shrinkage cavities, and surface depressions. The characteristics of low yield