A temperature control process for annealing cold-rolled steel balls

Abstract

The invention relates to the technical field of heat treatment process of steel, in particular to a cold-rolled steel ball annealing temperature control process, a cold-rolled steel ball annealing temperature control process, the cold-rolled steel ball annealing temperature control process comprising the following steps: step one: sending the cold-rolled steel to an annealing furnace, slowly heating it to between 400° and 500°, and keeping it warm at between 400° and 500° for 0.5h; step two: raising the temperature to 700-800° after 2.5h, and keeping it warm for 2h; step three: taking the steel out of the furnace after cooling to 600°, and water quenching for 0.5h; step four: air-cooling the cold-rolled steel ball after the water quenching, and the annealing operation is completed after the temperature drops to 70°-75°. The invention controls the annealing temperature of the cold-rolled steel ball by implementing the steps, so that the cold rolling process is smooth and smooth; the implementation of the steps of the invention does not require specific equipment, does not require the production equipment to be modified, and reduces the production cost.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment technology for steel, in particular to a temperature control process for annealing a cold-rolled steel ball. Background Art

[0002] Cold rolling usually adopts the longitudinal rolling method. The process of cold rolling production generally includes raw material preparation, pickling, rolling, degreasing, annealing (heat treatment), finishing, etc. Annealing is a metal heat treatment process in which the metal is heated to a certain temperature, kept for a sufficient time, and then cooled at an appropriate speed (usually slow cooling, sometimes controlled cooling). The purpose is to reduce hardness and improve machinability. In production, the annealing process is widely used. According to the different purposes of annealing required by the workpiece, there are many annealing process specifications. Commonly used ones include complete annealing, spheroidizing annealing, and stress relief annealing. The heating temperature of spheroidizing annealing is the key factor affecting whether the degree of spheroidization is complete or not. The appropriate heating temperature can not only ensure the disappearance of lamellar pearlite, but also retain a part of the carbides that are not completely dissolved in austenite as the spheroidization core, and finally form a normal spheroidized structure of coarse granular carbides. When the austenitizing temperature is very high, the carbides are completely dissolved and homogenized, and lamellar pearlite is always obtained after cooling. The cooling rate directly affects the size and uniformity of the carbide particles. If the cooling is too fast, the carbide particles are too fine, and there is a possibility of forming flaky carbides, which makes the hardness too high. If the cooling is too slow, the carbide particles are too coarse. In order to solve the above problems, a cold-rolled steel ball annealing temperature control process is proposed to control the temperature of the steel coil through step control. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a temperature control process for annealing cold-rolled steel balls, which solves the technical problem of unstable temperature control during annealing of cold-rolled steel balls.

[0004] The solution adopted by the present invention is: a cold-rolled steel ball annealing temperature control process, the cold-rolled steel ball annealing temperature control process comprising the following steps:

[0005] Step 1: Send the cold-rolled steel to the annealing furnace, slowly heat it to between 400° and 500°, and keep it at 400° to 500° for 0.5h;

[0006] Step 2: After 2.5 hours, raise the temperature to 700-800 degrees and keep it warm for 2 hours;

[0007] Step 3: Cool down to 600° and then take out of the furnace, and water quench for 0.5h;

[0008] Step 4: Air-cool the cold-rolled steel ball after water quenching. When the temperature drops to 70°-75°, the annealing operation is completed.

[0009] Preferably, in step three, the cold-rolled steel ball is water quenched for 0.5 h and then air-cooled, and the annealing operation is completed after the temperature drops to 70°-75°.

[0010] Beneficial effects of the present invention:

[0011] 1. The present invention controls the annealing temperature of the cold-rolled steel ball by implementing the steps, so that the cold-rolling process is smooth;

[0012] 2. The implementation of the steps of the present invention does not require any specific equipment, and there is no need to modify the production equipment, thereby reducing production costs. DETAILED DESCRIPTION

[0013] The above and other technical contents, features and effects of the present invention will be clearly presented in the detailed description of the following examples.

[0014] The following are various exemplary embodiments of the present invention.

[0015] Embodiment 1, a cold-rolled steel ball annealing temperature control process, the cold-rolled steel ball annealing temperature control process comprising the following steps:

[0016] Step 1: Send the cold-rolled steel to the annealing furnace, slowly heat it to between 400° and 500°, and keep it at 400° to 500° for 0.5h;

[0017] Step 2: After 2.5 hours, raise the temperature to 700-800 degrees and keep it warm for 2 hours;

[0018] Step 3: Cool down to 600° and then take out of the furnace, and water quench for 0.5h;

[0019] Step 4: Air-cool the cold-rolled steel ball after water quenching. When the temperature drops to 70°-75°, the annealing operation is completed.

[0020] Embodiment 2, on the basis of embodiment 1, in step 3, the cold-rolled steel ball is water quenched for 0.5h and then air-cooled, and the annealing operation is completed after the temperature drops to 70°-75°.

[0021] When the present invention is used, in step three, the temperature is lowered to 600° and then taken out of the furnace, and water quenching is performed for 0.5h. After this step, the cold-rolled steel can be air-cooled through an air-cooling hood, or the cold-rolled steel balls can be air-cooled. The purpose is to cool the cold-rolled steel balls, and there is no substantial difference in the results. During production, the steel can be selected according to its own adjustment, thereby reducing production conditions.

[0022] The above description is only for illustrating the present invention. It should be understood that the present invention is not limited to the above embodiments, and various variations that conform to the concept of the present invention are within the protection scope of the present invention.

Claims

1. A cold-rolled steel ball annealing temperature control process, characterized in that: The cold-rolled steel ball annealing temperature control process comprises the following steps: Step 1: Send the cold-rolled steel to the annealing furnace, slowly heat it to between 400° and 500°, and keep it at 400° to 500° for 0.5h; Step 2: After 2.5 hours, raise the temperature to 700-800 degrees and keep it warm for 2 hours; Step 3: Cool down to 600° and then take out of the furnace, and quench in water for 0.5h; Step 4: Air-cool the cold-rolled steel ball after water quenching. When the temperature drops to 70°-75°, the annealing operation is completed.

2. A cold-rolled steel ball annealing temperature control process according to claim 1, characterized in that: In step 3, the cold-rolled steel ball is water quenched for 0.5 h and then air-cooled. When the temperature drops to 70°-75°, the annealing operation is completed.