Ti-contained sulphuric acid dew-point corrosion resisting steel with tensile strength not less than 450 MPa)

Abstract

The invention relates to a Ti-contained sulphuric acid dew-point corrosion resisting steel with tensile strength not less than 450 MPa). The invention overcomes the defects of low sulphuric acid dew-point corrosion resistance and the like. the Ti-contained sulphuric acid dew-point corrosion resisting steel comprises the following chemical components in percentage by weight: 0.025-0.15% of C, 0.10-0.50% of Si, not more than 1.50% of Mn, not more than 0.020% of P, not more than 0.010% of S, 0.10-0.60% of Cu, 0.05-0.80% of W, 0.06-0.13% of Ti, not more than 0.080% of Al and balance of Fe and inevitable inclusions; and the sum of Cu, W and Ti is greater than 0.065% and smaller than 1.60%. The yield strength of the steel is at least 330 MPa, the tensile strength is not less than 450 MPa, and the percentage of elongtation is not less than 22%. The steel is delivered in the hot rolling state. The invention has the advantages of simple technique, low cost, favorable toughness match and favorable welding performance, and can be widely used for manufacturing boiler low-temperature components, flues, chimneys, tobacco curing boxes and special desulfurization equipment, thereby being beneficial to popularization and application.

Description

technical field [0001] The invention relates to a corrosion-resistant steel, specifically belongs to sulfuric acid dew-point corrosion-resistant steel, exactly belongs to sulfuric acid dew-point corrosion-resistant steel with Ti-containing tensile strength ≥ 450MPa. Background technique [0002] In order to respond to the national energy-saving and environmental protection policies, high-pollution enterprises that mainly burn coal must be treated, and production must be carried out after reaching the standard. Newly approved power generation, chemical, petroleum, steel and other projects must be equipped with desulfurization devices to make them burn The sulfur content in the flue gas is reduced to the emission standard allowed by the state. Since the humidity of the flue gas is usually high and the temperature is low, the content of diluted sulfuric acid per unit volume in the flue gas will increase accordingly. Therefore, the flue gas after desulfurization is still a highl...

AI Technical Summary

Problems solved by technology

The addition of Sn is likely to produce point defects on the surface of the steel plate, such as improper control of the hot rolling process, which is more likely to produce surface cracks; at the same time, Mo of 0.10-0.50% by weight significantly increases the production cost of the steel, and it is not disclosed in the document Test results of sulfuric acid corrosion resistance of the steel after adding Mo