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 for accurately controlling components in steel by utilizing converter steelmaking and RH-LF-RH refining. and the tapping temperature, prolong the furnace life of the converter, and give full play to the refining and desulfurization effect of the LF furnace. The RH vacuum secondary treatment eliminates the adverse effect of carbon increase in the LF process, reduces the amount of strong deoxidizer added, reduces the deoxidation inclusions in the steel, and improves the purity. It can meet the requirements of low-carbon, low-sulfur and high-purity component control of acid-resistant (anti-HIC and SCC) pipeline steel. Background technique [0002] Pipeline transportation is the most economical and reasonable transportation method for long-distance transportation of oil and natural gas, and has the characteristics of ...

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

Images