Solution and method for removing scale on surface of gear steel

Abstract

The invention discloses a solution and method for removing scale on the surface of gear steel. The solution is prepared from sulfosalicylic acid, hydrochloric acid and water according to the mass ratio of (10-15): (1-2): (85-100). The removal method comprises the following steps: (1) preparing a solution for removing the oxide scale on the surface of the gear steel; (2) gear steel with oxide scales is cut out; and (3) the gear steel with the oxide scale in the step (2) is put into the solution in the step (1) to be soaked, and after the oxide scale on the surface of the gear steel is dissolved and completely falls off, the gear steel is fished out, rinsed and dried. The solution provided by the invention is simple to prepare, the components of the solution are green and environment-friendly, the effect of removing the scale on the surface of the gear steel is good, the solution can be widely popularized and applied in the metallurgical industry, and the blank of removing the scale by using organic acid as a main solution component is filled.

Description

Technical Field

[0001] The invention relates to the technical field of metal material processing, and in particular to a solution and a method for removing iron oxide scale from the surface of gear steel. Background Art

[0002] During the production and manufacturing process of steel products, scale is often generated on the surface of steel products. Pickling is required to remove the surface iron oxide, make the product surface clean, and improve the surface structure of steel. For ordinary steel and general low-alloy steel, sulfuric acid pickling was mostly used in the past. Since the late 1980s, my country has gradually switched to pickling liquids mainly based on hydrochloric acid. During the pickling process of steel, a large amount of pickling waste liquid is generated, which is listed in the 2016 version of the "National List of Hazardous Wastes" under the number HW34. It is understood that nearly one million cubic meters of such waste liquid are discharged nationwide each year. This waste liquid not only contains a considerable amount of residual acid (about 100g in 1L), but also rich in ferrous salts (about 120g in 1L). Therefore, the waste acid liquid must be recycled, otherwise it will not only pollute the environment, but also cause serious waste of resources.

[0003] With the rapid development of my country's equipment manufacturing industry, the demand for high-quality gear steel is increasing. High-end gear steel is a high-tech steel used to manufacture gears. It is usually used in transmission parts of automobiles, engineering machinery and machinery manufacturing. It must not only have good strength and wear resistance, but also withstand impact, bending and contact stress during operation. It also requires small deformation, high precision and low noise. With the rapid development of technology in the machinery industry, gears are required to have a longer service life and safety factor, which puts higher requirements on the performance and quality of gear steel.

[0004] Gear steel is mostly low-carbon low-alloy steel. The commonly used pickling solution is a 75% hydrochloric acid aqueous solution. After pickling, not only a large amount of waste liquid will be produced, but also environmental pollution will be caused. Therefore, an environmentally friendly and effective solution and method for removing the iron oxide scale on the surface of gear steel is urgently needed to solve this problem. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a green, environmentally friendly and pollution-free solution and method for removing iron oxide scale on the surface of gear steel.

[0006] To achieve the above object, the present invention provides the following technical solutions: A solution for removing iron oxide scale on the surface of gear steel is prepared from sulfosalicylic acid, hydrochloric acid and water in a mass ratio of 10-15:1-2:85-100.

[0007] A method for removing iron oxide scale from the surface of gear steel comprises the following steps: (1) preparing a solution for removing iron oxide scale from the surface of gear steel; the solution is prepared by mixing sulfosalicylic acid, hydrochloric acid and water in a mass ratio of 10-15:1-2:85-100; (2) Cutting gear steel with iron oxide scale; (3) Soak the gear steel with oxidized iron scale in the solution prepared in step (1). After the oxidized iron scale is dissolved and removed, rinse and dry the gear steel.

[0008] Furthermore, in the method for removing iron oxide scale from the surface of gear steel described in the present invention, step (3) is carried out in a laboratory with a fume hood, and the corrosion temperature is room temperature.

[0009] Furthermore, in the method for removing iron oxide scale on the surface of gear steel described in the present invention, the iron oxide scale of the gear steel is formed by hot rolling, cold rolling or heat treatment process.

[0010] Furthermore, the method for removing iron oxide scale from the surface of gear steel of the present invention, wherein: in the step (3), as the immersion time of the iron oxide scale on the surface of the gear steel in the solution increases and the iron oxide scale reacts with the solute, the concentration of the solution will decrease. To ensure the dissolution and shedding speed and effect of the iron oxide scale, sulfosalicylic acid and hydrochloric acid can be added in appropriate amounts, and the mass ratio of sulfosalicylic acid to hydrochloric acid is 10-15:1-2, so that the pH value of the solution is maintained in the range of 0.8-1.2. The acidity of the solution can be detected in real time using an acid meter or a pH test pen.

[0011] Furthermore, in the method for removing iron oxide scale from the surface of gear steel described in the present invention, the gear steel with iron oxide scale is immersed in the solution for 0.5 to 1 hour in the step (3). The immersion time can be extended or shortened according to the thickness of the iron oxide scale on the surface of the gear steel and the degree of removal.

[0012] The beneficial effects of adopting the above technical solution are: 1. The solution for removing iron oxide scale used in the present invention is simple to prepare, has no irritating odor, is easy to use, and has good effects.

[0013] 2. The present invention adopts organic acid to solve the problem of removing iron oxide scale on the surface of gear steel, and can be widely promoted and applied in the metallurgical industry, filling the blank of removing iron oxide scale by using organic acid as the main solution component. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a macroscopic morphology of the oxide scale on the surface of the gear steel before the treatment in Example 1; Figure 2 This is a macroscopic morphology of the iron oxide scale on the surface of the gear steel after treatment in Example 1; Figure 3This is a macroscopic morphology of the iron scale on the surface of the gear steel before the treatment in Example 2; Figure 4 This is a macroscopic morphology of the iron oxide scale on the surface of the gear steel after treatment in Example 2; Figure 5 This is a macroscopic morphology of the iron scale on the surface of the gear steel before treatment in Example 3; Figure 6 This is the macroscopic morphology of the oxidized iron scale on the surface of the gear steel after treatment in Example 3. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0016] In this embodiment, after hot rolling, the gear steel generates iron oxide scale on its surface. Figure 1 As shown, the method for removing the iron oxide scale is as follows: (1) Preparation of a solution for removing iron oxide from the surface of gear steel: Add 10 parts of sulfosalicylic acid and 2 parts of hydrochloric acid to 85 parts of water in proportion by mass, stir evenly and set aside.

[0017] (2) Cut the gear steel with iron oxide scale on the surface to be processed.

[0018] (3) The gear steel with oxidized iron scale cut from step (2) is immersed in the solution prepared in step (1). After 1 hour, the oxidized iron scale is dissolved and removed. Then the gear steel is removed, rinsed, and dried. The results are as follows: Figure 2 shown.

[0019] Depend on Figure 2 It can be seen that the thick iron oxide scale on the surface of the gear steel was removed very cleanly. Example 2

[0020] In this embodiment, after hot rolling, the gear steel generates iron oxide scale on its surface. Figure 3 As shown, the method for removing the iron oxide scale is as follows: (1) Prepare a solution for removing iron oxide from the surface of gear steel: Add 15 parts of sulfosalicylic acid and 2 parts of hydrochloric acid to 100 parts of water in proportion by mass, stir evenly and set aside.

[0021] (2) Cut the gear steel with iron oxide scale on the surface to be processed.

[0022] (3) The gear steel with oxidized iron scale cut from step (2) is immersed in the solution prepared in step (1). After 1 hour, the oxidized iron scale is dissolved and removed. Then the gear steel is removed, rinsed, and dried. Figure 4 shown.

[0023] Depend on Figure 4It can be seen that the black oxide scale on the surface of the gear steel is removed cleanly with good results. Example 3

[0024] In this embodiment, after heat treatment, the gear steel generates iron oxide scale on its surface. Figure 5 As shown, the method for removing the iron oxide scale is as follows: (1) Preparation of a solution for removing iron oxide from the surface of gear steel: Add 12 parts of sulfosalicylic acid and 1.5 parts of hydrochloric acid to 90 parts of water in proportion by mass, stir evenly and set aside.

[0025] (2) Cut the gear steel with iron oxide scale on the surface to be processed.

[0026] (3) The gear steel with oxidized iron scale cut from step (2) is immersed in the solution prepared in step (1). After 1 hour, the oxidized iron scale is dissolved and removed. Then the gear steel is removed, rinsed, and dried. Figure 6 shown.

[0027] Depend on Figure 6 It can be seen that the black oxide scale on the surface of the gear steel is removed cleanly with good results.

Claims

1. A solution for removing iron oxide scale from the surface of gear steel, characterized in that: The solution is prepared by mixing sulfosalicylic acid, hydrochloric acid and water in a mass ratio of 10-15:1-2:85-100.

2. A method for removing iron oxide scale from the surface of gear steel, characterized in that: The specific steps include: (1) preparing the solution for removing iron oxide scale from the surface of gear steel as claimed in claim 1; (2) Cutting gear steel with iron oxide scale; (3) The gear steel with iron oxide scale cut from step (2) is soaked in the solution prepared in step (1). After the iron oxide scale on the surface of the gear steel is dissolved and removed, the gear steel is removed, rinsed and dried.

3. The method for removing iron oxide scale from the surface of gear steel according to claim 2, characterized in that: All steps were performed at room temperature without heating the solution.

4. The method for removing iron oxide scale from the surface of gear steel according to claim 2, characterized in that: The step (3) is carried out in a fume hood.

5. The method for removing iron oxide scale from the surface of gear steel according to claim 2, characterized in that: In step (3), the gear steel with oxidized iron scale is immersed in the solution for 0.5 to 1 hour.

6. The method for removing iron oxide scale from the surface of gear steel according to claim 2, characterized in that: The iron oxide scale of the gear steel is formed after hot rolling, cold rolling or heat treatment process.

Images