Smelting process for reducing layering defect of TP321 stainless steel seamless tube

A technology of TP321 and delamination defects, which is applied in the smelting process field of reducing delamination defects of TP321 stainless steel seamless pipes, can solve problems such as unstable control, achieve the effects of improving quality, increasing the pass rate of ultrasonic flaw detection, and reducing the total oxygen content

Active Publication Date: 2021-11-26
UNIV OF SCI & TECH BEIJING +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome at least one of the deficiencies of the prior art, aiming at the problem of unstable control of delamination defects of TP321 stainless steel seamless pipes at present, and to provide a smelting process for reducing delamination defects of TP321 stainless steel seamless pipes

Method used

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  • Smelting process for reducing layering defect of TP321 stainless steel seamless tube
  • Smelting process for reducing layering defect of TP321 stainless steel seamless tube

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Embodiment

[0056] (1) Crude molten steel is provided by the electric arc furnace: the raw materials of the electric arc furnace include scrap steel and returned materials, and the composition of the crude molten steel obtained after melting is shown in Table 2, that is, the composition of the molten steel in the AOD furnace; the composition of the molten steel in the AOD furnace is detected as 1475°C.

[0057] (2) AOD oxygen blowing decarburization: After the molten steel is put into the furnace, add 1500kg of lime, 200kg of magnesium oxide, oxygen-argon mixed blowing for decarburization, and gradually adjust the flow rate of oxygen-argon to reduce the burning of Cr element during the decarburization process. During this period, 800kg of high-carbon ferrochromium and 60kg of electrolytic manganese were added; after decarburization, the composition of molten steel is shown in Table 2.

[0058] (3) AOD ferrosilicon reduction: Add 300kg of lime and 450kg of ferrosilicon to the furnace, and ...

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Abstract

The invention relates to the technical field of stainless steel smelting, and provides a smelting process for reducing a layering defect of a TP321 stainless steel seamless tube. The smelting process comprises the following steps of providing crude molten steel by an electric arc furnace, carrying out AOD oxygen blowing decarburization, carrying out AOD ferrosilicon reduction, carrying out AOD aluminum deep deoxidation, tapping after AOD titanium alloying, carrying out soft stirring and calcium treatment in a steel ladle, and carrying out die casting. According to the smelting process, a process route of an electric arc furnace, a 20t AOD refining furnace, ladle treatment and the die casting is adopted, the Al element content in molten steel is strictly controlled before Ti alloying in the AOD refining furnace for deep deoxidation, after AOD tapping, silicon-calcium wires are fed into the steel ladle, high-melting-point Al2O3-MgO-TiOx inclusions in the molten steel are modified into low-melting-point inclusions, and the content of large-size SiO2-Al2O3-MnO-CaO and TiOx-MnO inclusions in the stainless steel is effectively reduced, the layering defect in the stainless steel seamless tube is reduced, and the ultrasonic flaw detection qualification rate of the stainless steel seamless tube is improved.

Description

technical field [0001] The invention relates to the technical field of stainless steel smelting, in particular to a smelting process for reducing delamination defects of TP321 stainless steel seamless pipes. Background technique [0002] Austenitic stainless steel is widely used in petroleum, nuclear industry, transportation, aerospace and other industrial sectors and daily necessities industry due to its excellent corrosion resistance, formability and strength and toughness in a wide temperature range. Its output accounts for about 70% of the total stainless steel. Ti element is widely used in stainless steel, mainly through the precipitation of TiN(C,N) particles of different sizes and uniform distribution to achieve stabilization, pinning and dispersion strengthening, thereby further improving the corrosion resistance and toughness of stainless steel. TP321 is a typical titanium-containing austenitic stainless steel, which has better high-temperature corrosion resistance...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/06C21C7/00C21C7/06C21C7/068C22C38/02C22C38/04C22C38/50C22C38/06
CPCC22C33/06C21C7/0006C21C5/005C21C7/06C21C7/0685C21C7/0056C22C38/02C22C38/04C22C38/50C22C38/06Y02P10/20
Inventor 成国光王启明代卫星黄宇仇云龙朱卫飞
Owner UNIV OF SCI & TECH BEIJING
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