Manufacturing method of high-temperature resistant and creep-resistant cast steel

Abstract

The invention discloses a manufacturing method of a high-temperature resistant and creep-resistant cast steel. A basic electric arc furnace is adopted for smelting, a steel ladle maintaining furnace is refined in an argon blowing mode, and argon protects pouring to produce the high-temperature resistant and creep-resistant cast steel. The specific steps are as follows: (1) adopting the basic electric arc furnace for smelting, which comprises: selecting furnace burden, dephosphorizing during the melting period, decarbonising during the oxidizing period, keeping reducing slag and strengthening deoxidation residual force; (2) after smelted by the electric furnace, entering the steel ladle maintaining furnace for argon blowing and refining; (3) controlling the pouring speed and the pouring temperature of the creep-resistant cast steel. The invention has the beneficial effect that the high temperature resistant and creep-resistant cast steel can be produced under the condition of no vacuumsmelting equipment, optimizes classical steelmaking technology, reduces equipment investment, does not occupy production sites and has small energy consumption; the manufacturing method can produce novel high temperature resistant and creep-resistant cast steel conforming to the European standard, and realizes the localization production of creep-resistant cast steel of million Kw super-critical turbines and large gas turbines.

Description

【Technical field】 [0001] The invention belongs to the technical field of casting, in particular to a method for manufacturing a high-temperature-resistant and creep-resistant steel casting. 【Background technique】 [0002] Creep-resistant cast steel is a special steel widely used in supercritical and ultra-supercritical steam turbines in the world. Europe has successfully developed GX-12CrMoWVNbN1011 creep-resistant cast steel. It has a creep strength of 100,000 hours. Because the chemical composition of this material is complex, its specification range is very narrow, the technical requirements are very high, and the production is very difficult. Therefore, China relies entirely on imports when using this kind of material. [0003] Domestic enterprises are also trying to produce such materials. When producing molten steel, they need to go through LF furnace for vacuum smelting, or carry out AOD argon-oxygen mixed blowing smelting, and then go through VD vacuum treatment; th...

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Problems solved by technology

[0003] Domestic enterprises are also trying to produce such materials. When producing molten steel, they need to go through LF furnace for vacuum smelting, or carry out AOD argon-oxygen mixed blowing smelting, and then go through VD vacuum treatment; the result is that in vacuum smelting equipment Large investment (generally more than 5 million yuan), large production site, long production process, complicated operation process, high energy consumption, and castings produced are scrapped due to defects such as pores and cracks

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