Low-cost Nb-free thin-gauge sulfuric acid dew point corrosion resisting steel and production method thereof

Abstract

The invention provides low-cost Nb-free thin-gauge sulfuric acid dew point corrosion resisting steel. The steel is characterized by comprising the following elements in percentage by mass: smaller than or equal to 0.12% of C, smaller than or equal to 0.55% of Si, 0.75% to 1.20% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.025% of S, 0.50% to 1.2% of Cr, 0.20% to 0.50% of Cu, smaller than or equal to 0.25% of Ni, 0.05% to 0.15% of Sb, smaller than or equal to 0.025% of Ti, smaller than or equal to 0.010% of V, 0.020% to 0.050% of Alt and 0.0005% to 0.0035% of Ca. The tissues of the steel disclosed by the invention are ferrite and pearlite; the heating temperature is increased; generation of relatively thick iron oxide scale is facilitated; transient temperature reduction of the surface iron oxide scale is increased during descaling of high-pressure water, so that shrinkage of the surface iron oxide scale is intensified, the iron oxide scale is easier to remove from a base body, the descaling efficiency is improved, and iron oxide scale residues are fundamentally reduced.

Description

technical field [0001] The invention belongs to the field of metallurgy, and relates to a low-cost Nb-free thin gauge sulfuric acid dew point corrosion-resistant steel and a production method thereof. Background technique [0002] In order to achieve the strength requirement of 345MPa yield strength, the traditional process uses controlled rolling and Nb microalloying elements to carry out fine-grain strengthening to increase strength. However, as the steel industry market continues to weaken, steel prices plummet, and alloy elements should be appropriately reduced. The production cost can be reduced to a certain extent by reducing the content or improving the process. The development of a low-cost Nb-free thin-gauge sulfuric acid dew point corrosion-resistant steel and its production method is very important for how to effectively reduce the cost. [0003] Sulfuric acid dew point corrosion-resistant steel contains alloying elements such as Mn, Cr, Cu, Sb, etc. During the he...

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Problems solved by technology

[0004] According to the knowledge of the inventor, the existing literature (research on the production process characteristics of 304 stainless steel hot rolling, master's thesis of Northeastern University, 2009) reported that by adjusting and optimizing the heating process system, a reasonable heating temperature control range was determined to be between 1230 and 1260 °C time, it can solve the quality defects of 304 stainless steel surface oxide scale and roll traces, but this method is not suitable for solving the surface defects of low-cost Nb-free thin gauge sulfuric acid dew point corrosion-resistant steel, in addition to increasing the heating temperature, it is also necessary to adopt an appropriate phosphorus removal process , the combination of the two can achieve the best effect

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