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Low alloy steel for resisting sulfuric acid dew point corrosion and production method thereof

A technology of dew point corrosion and sulfuric acid resistance, applied in temperature control and other directions, can solve the problems of relatively strict content requirements, unsatisfactory sulfuric acid dew point corrosion resistance, and affecting the processing performance of steel, and achieve the effect of superior sulfuric acid dew point corrosion resistance

Inactive Publication Date: 2010-09-15
MAANSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

For example, the patent 02800218.0 of Nippon Steel Corporation has developed a steel grade that has excellent sulfuric acid dew point corrosion resistance at low temperature and low concentration and high temperature and high concentration. This steel grade uses a certain amount of silicon, copper and antimony. The combination of elements can improve the sulfuric acid dew point corrosion resistance, but in the steel with low carbon content, silicon is an element that makes the sulfuric acid corrosion resistance unfavorable.
The patent application of Nippon Steel Corporation (application number 200680006324.X) discloses a sulfuric acid dew-point corrosion-resistant steel. The chemical composition of the steel is relatively complex, and the requirements for the content of S and Si are relatively strict, which increases the smelting cost of the steel; Jinan Iron and Steel General Works Patent No. 90101258.0 developed a method of adding copper, chromium, and vanadium on the basis of ordinary carbon steel for microalloying to improve the resistance to sulfuric acid dew point corrosion of steel, but vanadium in steel only plays a role in improving strength. , comprehensive resistance to sulfuric acid dew point corrosion is not ideal
Anshan Iron and Steel Company Patent No. 89109017.7 designed a copper-chromium-rare earth series low-alloy sulfuric acid dew-point corrosion-resistant steel. The boiler air preheater made of this steel has a service life of more than 2.5 times that of ordinary carbon steel. In the actual production process Among them, the steel containing rare earth will make iron and steel smelting more difficult, the stability of molten steel will deteriorate, and at the same time affect the processing performance of steel

Method used

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  • Low alloy steel for resisting sulfuric acid dew point corrosion and production method thereof
  • Low alloy steel for resisting sulfuric acid dew point corrosion and production method thereof
  • Low alloy steel for resisting sulfuric acid dew point corrosion and production method thereof

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Effect test

Embodiment 1

[0020] Table 1 shows the chemical composition of a low-alloy sulfuric acid dew-point corrosion-resistant steel of the present invention. Production methods include steelmaking, continuous casting and hot rolling, pretreatment of molten iron, converter smelting, argon blowing station, LF furnace refining, feeding FeS line before LF furnace leaves the station, adjusting [S] to the target value, weak stirring time 15min ; The molten steel is cast into a slab of 230mm×1500mm on a continuous casting machine, and the temperature of the tundish is controlled at 15-30°C above the liquidus temperature during the continuous casting process. The slab is hot-rolled by the controlled rolling and controlled cooling process, and the casting slab is hot-charged. The temperature of the furnace is 1240°C. During the rough rolling process, the reduction rate of the first three passes of the first roll should be increased as much as possible; The final rolling temperature is 830°C; laminar flow c...

Embodiment 2

[0023] Table 1 shows the chemical composition of a low-alloy sulfuric acid dew-point corrosion-resistant steel of the present invention. Production methods include steelmaking, continuous casting and hot rolling, using molten iron pretreatment, converter smelting, argon blowing station, LF furnace refining, feeding FeS line before LF furnace leaves the station, adjusting [S] to the target value, weak stirring time 18min ; The molten steel is cast into a slab of 240mm×1600mm on a continuous casting machine, and the temperature of the tundish is controlled at 15-30°C above the liquidus temperature during the continuous casting process. The slab is hot-rolled by controlled rolling and controlled cooling process, and the cast slab is hot-charged. The furnace temperature is 1250°C. During the rough rolling process, the reduction rate of the first three passes of the first roll should be increased as much as possible; the finish rolling entrance temperature is 1230°C. The final roll...

Embodiment 3

[0026] Table 1 shows the chemical composition of a low-alloy sulfuric acid dew-point corrosion-resistant steel of the present invention. Production methods include steelmaking, continuous casting and hot rolling, pretreatment of molten iron, converter smelting, argon blowing station, LF furnace refining, feeding FeS line before LF furnace leaves the station, adjusting [S] to the target value, weak stirring time 20min ; The molten steel is cast into a slab of 250mm×1800mm on a continuous casting machine, and the temperature of the tundish is controlled at 15-30°C above the liquidus temperature during the continuous casting process. The slab is hot-rolled by controlled rolling and controlled cooling process, and the cast slab is hot-charged. The furnace temperature is 1250°C. During the rough rolling process, the reduction rate of the first three passes of the first roll should be increased as much as possible; the finish rolling entrance temperature is 1230°C. The final rolling...

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PUM

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Abstract

The invention discloses a low alloy steel for resisting sulfuric acid dew point corrosion, which comprises the following components in mass percent: less than or equal to 0.10% of C, 0.10-0.40% of Si, 0.40-1.00% of Mn, less than or equal to 0.025% of P, less than or equal to 0.035% of S, 0.025-0.040% of Als, 0.10-0.30% of Ni, 0.30-0.50% of Cu, 0.50-1.00% of Cr, 0.04-0.15% of Sb and the balance of Fe and inevitable impurity elements. The production method comprises the steps of steel making, continuous casting and hot rolling, wherein in the steel making process, a ladle refining furnace (LF furnace) is used for refining, FeS Lines are fed before the LF furnace is out of the station, [S] is adjusted to a target value, and the weak stirring time is longer than or equal to 12 min; in the continuous casting process, the temperature of a pouring box is controlled above liquidus temperature (15-30 DEG C); and in the hot rolling process, the controlled rolling and controlled cooling process is adopted, the tapping temperature of a casting blank is higher than or equal to 1230 DEG C, the finish rolling temperature is controlled between 830 DEG C and 880 DEG C, and the coiling temperature is controlled between 600 DEG C and 640 DEG C.

Description

technical field [0001] The invention relates to a low-alloy steel capable of ensuring excellent sulfuric acid dew point corrosion resistance under the sulfuric acid dew point environment and a production method thereof. Background technique [0002] In industrial production, since the heavy oil or coal of oil-fired or coal-fired boilers usually contains 2% to 3% of sulfur, there will be about 0.2% of sulfur dioxide in the flue gas after combustion, of which 1% to 2% of sulfur dioxide is affected. Sulfur trioxide is produced by the catalysis of ash and metal oxides, which then combines with the moisture contained in the combustion gas and air to form sulfuric acid. When the ambient temperature is below 150°C, the sulfuric acid in the flue gas has a dew point, and the sulfuric acid is at Condensation and corrosion of the metal surface is the so-called sulfuric acid dew point corrosion. [0003] Aiming at the problem of sulfuric acid dew point corrosion, steel materials that c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/60C21C7/00B21B37/74
Inventor 马玉平张建杨兴亮张武刘国平张宜刘永刚赵勇方政舒宏富张晓峰
Owner MAANSHAN IRON & STEEL CO LTD