Corrosion-resistant alloy steel bar and preparation method therefor

Abstract

Provided in the present application are a corrosion-resistant alloy steel bar and a preparation method therefor, wherein the corrosion-resistant alloy steel bar comprises, in percentage by weight: 0.05-0.25% of C, 1.05-2% of Si, 0.3-1.5% of Mn, 0.5-2.5% of Cr, 0.05-1% of Ni, 0.001-0.005% of O, 0.001-0.0035% of S, 0.005-0.1% of Ti, 0.005-0.1% of Al, 0.005-0.03% of V, and 0.005-0.03% of Nb, with the balance being Fe and inevitable impurities. The preparation method therefor comprises the successive steps of smelting, refining, continuous casting, rolling and cooling. In the present application, elements such as Si, Ti, Al and Mn are used for compensating for the reduction in corrosion resistance caused by a decrease in the content of Cr, such that the production cost of the corrosion-resistant alloy steel bar are greatly reduced.

1 . A corrosion-resistant alloy steel bar, wherein, in percentage by weight, the corrosion-resistant alloy steel bar comprises 0.05% to 0.25% of C, 1.05% to 2% of Si, 0.3% to 1.5% of Mn, 0.5% to 2.5% of Cr, 0.05% to 1% of Ni, 0.001% to 0.005% of O, 0.001% to 0.0035% of S, 0.005% to 0.1% of Ti, 0.005% to 0.1% of Al, 0.005% to 0.03% of V, 0.005% to 0.03% of Nb, and the balance of Fe and inevitable impurities;
 wherein, the content of Si and Mn satisfies 2≤Si/Mn≤5; the content of Si and Cr satisfies 0.75≤Si/Cr≤1.5; and the content of Ti and Al satisfies 0.02%≤(Ti+Al)≤0.2%.   
     
     
         2 . The corrosion-resistant alloy steel bar of  claim 1 , wherein the content of Si is in a range from 1.2% to 1.8%;
 and/or, the content of Mn is in a range from 0.4% to 1%;   and/or, the content of Cr is in a range from 0.85% to 2%.   
     
     
         3 . The corrosion-resistant alloy steel bar of  claim 2 , wherein,
 the content of Si is in a range from 1.35% to 1.65%;   and/or, the content of Mn is in a range from 0.45% to 0.75%;   and/or, the content of Cr is in a range from 1.35% to 1.75%.   
     
     
         4 . The corrosion-resistant alloy steel bar of  claim 1 , wherein the content of C is in a range from 0.05% to 0.15%. 
     
     
         5 . The corrosion-resistant alloy steel bar of  claim 4 , wherein the content of C is in a range from 0.07% to 0.12%. 
     
     
         6 . The corrosion-resistant alloy steel bar of  claim 1 , wherein,
 the content of Ti is in a range from 0.01% to 0.075%;   and/or, the content of Al is in a range from 0.01% to 0.075%.   
     
     
         7 . A method for preparing the corrosion-resistant alloy steel bar of  claim 1 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence. 
     
     
         8 . The method of  claim 7 , wherein raw materials for preparing the corrosion-resistant alloy steel bar comprise ferro-silicon alloy and silicon-manganese alloy, and a mass ratio of ferro-silicon alloy to silicon-manganese alloy is in a range from 2:1 to 5:1. 
     
     
         9 . The method of  claim 7 , wherein,
 during the process of continuous casting, a casting speed is in a range from 2.5 m/min to 3.5 m/min;   and/or, during the process of cooling, a temperature of steel bar when moved onto a cooling bed is in a range from 820° C. to 1,000°° C.;   and/or, the process of rolling comprises the steps of heating the continuous casting steel billet, rough rolling and finish rolling.   
     
     
         10 . The method of  claim 9 , wherein a temperature for heating the continuous casting steel billet is in a range from 1,150°° C. to 1,250° C.; a temperature for the rough rolling is in a range from 1,000°° C. to 1,120° C.; and a temperature for the finish rolling is 1000° C. or higher. 
     
     
         11 . A method for preparing the corrosion-resistant alloy steel bar of  claim 2 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence. 
     
     
         12 . A method for preparing the corrosion-resistant alloy steel bar of  claim 3 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence. 
     
     
         13 . A method for preparing the corrosion-resistant alloy steel bar of  claim 4 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence. 
     
     
         14 . A method for preparing the corrosion-resistant alloy steel bar of  claim 5 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence. 
     
     
         15 . A method for preparing the corrosion-resistant alloy steel bar of  claim 6 , wherein the method comprises the processes of smelting, refining, continuous casting, rolling and cooling in sequence.