Process for producing anti-acid pipeline steel by Ruhrstahl Heraecus (RH)-ladle furnace (LF)-RH refining

Abstract

The invention discloses a process for producing an anti-acid pipeline steel by Ruhrstahl Heraecus (RH)-ladle furnace (LF)-RH refining. In the process, the composition of molten steel is controlled by converter smelting and RH-LF-RH refining process, so as to produce a low-carbon low-sulfur anti-acid (hydrogen-induced cracking HIC and stress corrosion cracking SCC resistant) pipeline steel. The specific flow is as follows: pre-desulphuzation of molten steel - converter smelting-primary RH vacuum refining - LF refining desulphuzation - secondary RH vacuum refining - continuous casting. By the secondary RH vacuum refining process, the decarburization burden of the converter and the oxidability of the molten steel can be reduced, and the adverse effect caused by recarburization in the LF refining process can be eliminated; furthermore, the use of a strong deoxidizer is reduced, the production is stabilized, and the composition of the molten steel is ensured to be controlled within a production target stably to meet the control requirements of the anti-acid pipeline steel on the low-carbon low-sulfur and high-purity composition. The carbon content of the finished steel produced by the process of the invention can be stably controlled to be 0.03% to 0.04%, and the sulfur content is stably controlled to be less than or equal to 0.0010%.

Description

Technical field [0001] The invention belongs to the field of smelting and production of high-grade acid-resistant pipeline steel, and relates to a smelting process that uses converter steelmaking and RH-LF-RH refining to accurately control the components in steel. The process can greatly reduce the burden of converter decarburization and reduce molten steel oxidation. And the tapping temperature, extend the converter life, and can give full play to the refining and desulfurization effect of the LF furnace. The RH vacuum secondary treatment eliminates the adverse effects of carbon increase in the LF process, reduces the amount of strong deoxidizers, reduces deoxidation inclusions in the steel, and improves purity It has high temperature, uniform heat composition, stable production process and strong operability, which meets the composition control requirements of low carbon, low sulfur and high purity for acid-resistant (anti-HIC and SCC) pipeline steel. Background technique [00...

AI Technical Summary

Problems solved by technology

The above process only has one RH vacuum refining process, which increases the smelting burden of the converter, reduces the furnace age, and the purity of molten steel is poor. At the same time, the requirements for the LF and RH refining processes are also relatively strict, that is, the raw materials and equipment for each link of the overall metallurgical process , operation level requirements are relatively high, it is more difficult to stabilize production

The control of carbon and sulfur components in the finished steel is unstable, and the acid resistance (resistance to HIC and SCC) cannot be stably up to the standard

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