Method for dehydrogenating low-carbon stainless steel in refining furnace

A refining furnace and stainless steel technology, applied in the field of dehydrogenation of low-carbon stainless steel in the refining furnace, to achieve the effect of improving performance

Inactive Publication Date: 2012-05-23
SHANXI TAIGANG STAINLESS STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The current method only focuses on dehydrogenation after reduction, the dehydrogenation rate is 30-60%, and the rate of hydrogen content in steel after dehydrogenation is more than 2ppm is 11%.

Method used

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  • Method for dehydrogenating low-carbon stainless steel in refining furnace

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] This embodiment is carried out on a 90-ton double-station VOD refining furnace. Two bottom blowing gas supply devices are installed at the bottom of the ladle used. The maximum flow rate of single bottom gas supply is 600L / min, and the highest vacuum degree of VOD is 80Pa.

[0019] The smelted steel type TGOG13Cr-2, the mass percentage of the chemical composition of the finished steel type is shown in Table 1:

[0020] Table 1

[0021] the element

C%

Si%

Mn%

P%

S%

standard

≤0.030

0.15-0.40

0.50-0.65

≤0.018

≤0.008

the element

Cr%

Ni%

Mo%

V%

N%

standard

12.50-14.50

4.00-6.00

1.90-2.10

0.07-0.11

≤0.050

[0022] The steps of this embodiment are dehydrogenation by blowing argon at the bottom of the ladle under vacuum after carbon deoxidation and reduction under vacuum, and the steps are characterized by:

[0023] 1. In the ea...

Embodiment 2

[0037] This embodiment is carried out on a 90-ton double-station VOD refining furnace. Two bottom blowing gas supply devices are installed at the bottom of the ladle used. The maximum flow rate of single bottom gas supply is 600L / min, and the highest vacuum degree of VOD is 80Pa.

[0038] The smelted steel grade TP316LN, the mass percentage of the chemical composition of the finished steel grade is shown in Table 2:

[0039] Table 2

[0040] the element

C%

Si%

Mn%

P%

S%

standard

≤0.020

0.40-0.65

1.00-1.80

≤0.025

≤0.005

the element

Cr%

Ni%

Mo%

Cu%

N%

standard

16.80-17.80

12.00-13.00

2.20-2.80

≤0.10

≤0.050

[0041] The steps of this embodiment are dehydrogenation by blowing argon at the bottom of the ladle under vacuum after carbon deoxidation and reduction under vacuum, and the steps are characterized by:

[0042] 1. In the early ...

Embodiment 3

[0056] This embodiment is carried out on a 90-ton double-station VOD refining furnace. Two bottom blowing gas supply devices are installed at the bottom of the ladle used. The maximum flow rate of single bottom gas supply is 600L / min, and the highest vacuum degree of VOD is 80Pa.

[0057]The smelted steel grade is 304L, and the chemical composition (mass percentage) of the finished steel grade is shown in Table 3:

[0058] table 3

[0059]

[0060] The steps of this embodiment are dehydrogenation by blowing argon at the bottom of the ladle under vacuum after carbon deoxidation and reduction under vacuum, and the steps are characterized by:

[0061] 1. In the early stage of molten steel treatment, use high-carbon deoxygenation boiling dehydrogenation molten steel under high vacuum to obtain the initial chemical composition mass percentage in VOD refining furnace:

[0062] C 0.31; Si 0.10; Mn 1.45; P 0.022; S 0.011; Cr 18.17; Ni 9.63;

[0063] Mo 0.02; N 0.1810; H 0.00023; ...

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Abstract

The invention relates to a method for dehydrogenating low-carbon stainless steel in a refining furnace. The method comprises the following steps of: carbon deoxidization in a vacuum state and strong stirring for dehydrogenating in a vacuum state after reduction; the steps are characterized in that: in the first step, at the early stage of molten steel processing, the molten steel dehydrogenated by utilizing high-carbon deoxidization boiling under a high vacuum degree in a VOD (vacuum oxygen decarburization) refining furnace has not more than 6ppm of initial hydrogen content and 0.25-0.35 percent of carbon content, and under the condition that the vacuum degree is not more than 3*10<2>Pa, the carbon deoxidization boiling time is 15-20min; and in the second step, after reduction, strong stirring for dehydrogenating is carried out by utilizing steel ladle bottom argon blowing under the high vacuum degree, after all reduction materials are added for 2min and under the condition that the vacuum degree is not more than 3*10<2>Pa, steel ladle bottom argon blowing is carried out, the argon intensity is not less than 12L/min, and stirring dehydrogenating is carried out for 16-20min. According to the method disclosed by the invention, the dehydrogenating effect is enhanced, the dehydrogenating rate can reach 50-80 percent so that the hydrogen content in the stainless steel is completely reduced to 1.5ppm-0.5ppm from the initial 2-6ppm, and the requirements of the low-carbon stainless steel for the hydrogen content are achieved.

Description

technical field [0001] The invention relates to a method for dehydrogenating low-carbon stainless steel in a refining furnace, in particular to a method for dehydrogenating stainless steel with a carbon content not greater than 0.05% in a VOD refining furnace. Background technique [0002] Hydrogen is a harmful element in stainless steel. Hydrogen has a solid solubility of a few parts per million to more than a dozen in stainless steel. When the hydrogen exceeds the solid solubility in steel, bubbles will form during the solidification process of the steel. When it is serious, it will cause the steel ingot to rise; when it is light, it will extend during thermal processing to form a small amount of fine cracks, that is, white spots, which will cause the plasticity and toughness of stainless steel to decrease, and will be harmful to the quality of stainless steel. For this reason, some low-carbon stainless steels require that the hydrogen content in the steel should not exce...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C7/04C21C7/072
Inventor 张增武
Owner SHANXI TAIGANG STAINLESS STEEL CO LTD
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