Production method of strip steel for galvanized tube

Abstract

The invention provides a production method of strip steel for a galvanized tube. The steel for the galvanized tube comprises chemical components including, by weight percent, 0.04 to 0.12% of C, 0.30to 0.60% of Mn, not larger than 0.04% of Si, 0.025to 0.045% of P, not larger than 0.020% of S, 0.010 to 0.050% of Als, not larger than 0.010% of As, 0.010 to 0.030% of Ti, 0.01 to 0.14% of Cu and thebalance iron and inevitable impurities. The content of elements of C, Si, As, P, Ti and the like can be accurately determined, the influence of the chemical component range on the galvanization quality can be avoided, and the adverse effect of the chemical component on sudden protruding, over thickness and the like of a galvanizing coat can be avoided; through strict control over the content of the As in the steel, increasing of the descaling passes, reducing the reeling temperature and the like, the thickness of the scale layer on the surface layer of strip steel can be effectively reduced, the smoothness of the steel strip surface layer can be improved, and the aim of improving the galvanization quality is achieved.

Description

technical field [0001] The invention relates to a method for producing special steel, in particular to a method for producing strip steel for galvanized pipes that can improve the quality of the galvanized layer. Background technique [0002] Galvanized steel pipe is a welded steel pipe coated with a zinc layer on the surface. Galvanizing can increase the corrosion resistance of the steel pipe and prolong its service life. Galvanized pipes are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipelines in the petroleum industry, especially offshore oil fields, and oil heaters and condensation pipes for chemical coking equipment. Pipes for coolers, coal distillation washing oil exchangers, trestle piles, and support pipes for mine tunnels, etc. At present, the pillars of highway guardrails are also widely made of galvanized pipes. The steel used for galvanized p...

AI Technical Summary

Problems solved by technology

According to the feedback from downstream customers, during the hot-dip galvanizing process of galvanized pipe steel strips produced according to conventional processes, there are generally phenomena such as uneven galvanizing and excessively thick galvanized layers.

The reason is that the strip steel used as raw material for galvanized pipes has problems such as rough surface and thickness of oxide scale. In addition, the chemical composition ratio of the steel used for galvanized pipes will also have a serious impact on the quality of galvanizing.

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