Steel plate resistant to sulfuric acid dew point corrosion and manufacturing method for steel plate

Abstract

The invention discloses a strong-strength and low-yield ratio steel plate resistant to sulfuric acid dew point corrosion and a manufacturing method for the steel plate. The steel plate comprises the following chemical components in percentage by mass: 0.06 to 0.10 percent of C, 0.15 to 0.50 percent of Si, 0.90 to 1.20 percent of Mn, less than or equal to 0.012 percent of P, less than or equal to 0.008 percent of S, 0.40 to 0.70 percent of Cr, 0.15 to 0.45 percent of Ni, 0.20 to 0.50 percent of Cu, 0.02 to 0.04 percent of Al, 0.02 to 0.05 percent of V, 0.015 to 0.04 percent of Nb, 0.01 to 0.02 percent of Ti, 0.0005 to 0.005 percent of Ca, less than or equal to 0.007 percent of N and the balance of Fe and inevitable impurity elements. The steel plate resistant to sulfuric acid dew point corrosion is directly manufactured by a continuous casting billet of 150mm or more, and the manufacturing method comprises the following steps of heating the continuous casting billet to 1,180 to 1,230 DEG C, preserving heat for 2 to 3 hours, performing rolling after high-pressure water scale removal, cooling the continuous casting billet to 500 to 620 DEG C at the cooling speed of 7 to 15 DEG C/s, and performing straightening and cooling to obtain the steel plate resistant to sulfuric acid dew point corrosion. According to the steel plate and the manufacturing method, a trace amount of Ca, and Nb and V favorable for improving the toughness of steel are added on the basis of Cu-Cr-Ni-Ti anticorrosion, and the content of each element is reasonably set, so that the strength and toughness of the steel are improved on the basis of ensuring the resistance of the steel to the sulfuric acid dew point corrosion, and the yield ratio is lowered.

Description

technical field [0001] The invention belongs to a steel plate for sulfuric acid dew point corrosion resistance and a manufacturing method thereof, in particular to a sulfuric acid dew point corrosion resistant steel plate with a yield strength of 500 MPa, low yield ratio and high toughness, and a manufacturing method thereof. Background technique [0002] Sulfuric acid dew point corrosion will cause great damage to the equipment in metallurgy, electric power, petroleum and chemical flue gas treatment systems that use coal or heavy oil as the main fuel. Non-metallic coatings can be used to avoid sulfuric acid dew point corrosion of components to a certain extent. However, the construction is difficult and affects the heat transfer efficiency at the same time. The most ideal solution to this problem is to use steel with sulfuric acid dew point corrosion resistance in the environment of sulfuric acid dew point corrosion. [0003] At present, the steels resistant to sulfuric a...

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Problems solved by technology

The disadvantage is that the yield strength of the sulfuric acid dew-point corrosion-resistant steel involved in this patent is too large to reach more than 690MPa, resulting in an excessively high yield ratio (yield strength/tensile strength) of the sulfuric acid dew-point corrosi

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