A method for producing a low-alloy single-rolled steel plate for cold spinning

Abstract

The application discloses a production method of low-alloy single-rolling steel plate for cold spinning processing, which comprises the following steps: (1) adding new blank component design; (2) designing slow speed 1.10-1.30 m / min and weak electromagnetic stirring process in a continuous casting process, and the current is 160-180 A and the frequency is 6-11 Hz; (3) producing 20-30 mm thickness specification Q355 steel plate from 150-220 mm section blank, adjusting blank heating temperature 1200-1250 DEG C, heating time 0.8-1.6 min / mm, and uniformly heating the blank; and (4) adopting higher rolling temperature, two opening is less than 980 DEG C, final rolling is 800-900 DEG C, and the re-red temperature is increased to 660-700 DEG C, so that the strength can be increased and the higher elongation rate can be maintained. The application has the advantages that the strength performance and the elongation rate of the 20-30 mm thickness specification Q355 grade steel plate are improved, the service life of the workpiece is prolonged, and the machining performance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel metallurgy, and particularly relates to a production method of low-alloy single-rolled steel plate for cold spinning processing. BACKGROUND

[0002] With the rapid development of the automobile industry and the increasing demand of consumers for vehicle performance, cold spinning processing of wheel hubs as an advanced manufacturing technology plays an increasingly important role in modern manufacturing. It not only meets the demand of the automobile manufacturing industry for high-precision and high-quality parts, but also promotes the automobile manufacturing industry to develop in a more environmentally friendly and efficient direction. Among them, the quality requirements of mining vehicles for wheel hubs are higher, and the strength and elongation of the existing 20-30mm thickness specification Q355 grade steel plate cannot be considered, the anti-deformation ability is limited and it is not easy for customers to process and use, such as shown in FIG. 1, so the service life is shorter, which undoubtedly reduces the performance and quality of the wheel hub and increases the processing cost. Figure 1 SUMMARY

[0003] The purpose of the application is to solve the problems of low strength and elongation, short service life and high processing cost of existing single-rolled steel plates. The application provides a production method of low-alloy single-rolled steel plate for cold spinning processing, which can improve the strength performance and elongation of 20-30mm thickness specification Q355 grade steel plate, improve the service life of the workpiece, and improve the processing performance.

[0004] In order to achieve the above purpose, the application adopts the following technical scheme:

[0005] A production method of low-alloy single-rolled steel plate for cold spinning processing, specifically comprising:

[0006] (1) adding new blank composition design;

[0007] (2) setting the continuous casting process parameters: designing slow pulling speed 1.10-1.30m / min and weak electromagnetic stirring process in the continuous casting process, current 160-180A, frequency 6-11Hz;

[0008] (3) setting the heating parameters: producing 20-30mm thickness specification Q355 steel plate by using 150-220mm section billet, adjusting the billet heating temperature to 1200-1250℃, heating time 0.8-1.6min / mm, and making the billet heating uniform;

[0009] (4) setting the rolling parameters: using higher rolling temperature, two openings ≤980℃, finish rolling 800-900℃, and improving the red temperature to 660-700℃, so as to improve the strength and still maintain high elongation.

[0010] ​Further, in the step (1), the blank composition includes, in percentage by mass: C: 0.08-0.12, Mn: 1.40-1.60, P≤0.015, S≤0.005, Si: 0.1-0.3, Nb: 0.02-0.04, Cr: 0.1-0.2, Ti: 0.005-0.02.

[0011] Further, in the step (1), the blank composition includes, in percentage by mass: C: 0.09, Mn: 1.46, P: 0.012, S: 0.003, Si: 0.21, Nb: 0.026, Cr: 0.16, Ti: 0.014.

[0012] Further, in the step (2), the drawing speed is 1.1 m / min, the electromagnetic stirring process is used, the current is 180 A, and the frequency is 6 Hz.

[0013] Further, in the step (3), a 220 mm section blank is used, the heating and tapping temperature is 1230 ℃, and the heating time is 1.0 min / mm.

[0014] Further, in the step (4), the finishing temperature is 952 ℃, the final rolling temperature is 868 ℃, the water entry temperature is 804 ℃, and the red temperature is 677 ℃.

[0015] In the technical scheme of the present application, by using the high-temperature rolling, high water entry temperature process, and high red temperature design, the cooling intensity is ensured, the quenching structure is reduced, the surface processing cracking is reduced, the processing performance and strength performance are improved, ReH≥400 MPa, Rm≥500 MPa, the deformation resistance of the workpiece is improved, the service life is increased, the elongation performance is improved, A≥25%, the customer processing and use are facilitated, and the processing cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a physical map of a conventional Q355 grade steel plate in the prior art;

[0017] Figure 2 It is a physical map of a Q355 grade steel plate in the embodiment of the present application;

[0018] Figure 3 It is a metallographic structure map of a Q355 grade steel plate in the embodiment of the present application. DETAILED DESCRIPTION

[0019] EMBODIMENT

[0020] In order to make the present application clearer, the present application is further described below in combination with the drawings, and the specific embodiments described herein are only used to explain the present application, and do not limit the present application.

[0021] In this embodiment, taking the order of steel grade Q355B, 24.5*2400mm specification as an example, the component design is as follows:

[0022]

[0023] (1) Continuous casting process: drawing speed 1.1 m / min, electromagnetic stirring process, current 180A, frequency 6Hz;

[0024] (2) Rolling mode: using 220mm section billet, heating temperature is 1230℃, heating time is 1.0min / mm.

[0025] (3) The rolling parameters are shown in the following table, high temperature rolling, high water temperature process, high red temperature design are adopted, which not only ensures the cooling intensity, but also reduces the quenching structure, reduces the surface processing cracking and improves the processing performance:

[0026] After adopting the method of the present application, the metallographic structure diagram and the physical diagram of the low alloy single-rolled steel plate are shown in Figure 3 and Figure 2 , and the specific mechanical properties are as follows:

[0027]

[0028] The present application improves the strength performance and elongation of the 20~30mm thick steel plate by redesigning the production mode of the Q355 grade steel plate, so as to improve the service life of the workpiece and improve the processing performance. The workpiece rejection rate is reduced by 5%, the annual demand is about 5000 tons, and the loss of the defective product is about 1500 yuan / ton. The annual benefit N=5000 tons / year*5%*1500 yuan / ton=375,000 yuan.

[0029] In addition to the above embodiments, the present application can also have other implementation manners. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A low alloy single-rolled steel plate production method for cold spinning processing, characterized in that: (1) a new blank composition design: the blank composition includes, in terms of mass percentage: C: 0.08-0.12, Mn: 1.40-1.60, P≤0.015, S≤0.005, Si: 0.1-0.3, Nb: 0.02-0.04, Cr: 0.1-0.2, Ti: 0.005-0.02; (2) continuous casting process parameter setting: slow drawing speed 1.10-1.30 m / min and weak electromagnetic stirring process are designed in the continuous casting process, the current is 160-180 A, and the frequency is 6-11 Hz; (3) heating parameter setting: 150-220 mm section blank is used to produce 20-30 mm thickness specification Q355 steel plate, the blank heating temperature is adjusted to 1200-1250℃, and the heating time is 0.8-1.6 min / mm, so that the blank is uniformly heated; (4) rolling parameter setting: higher rolling temperature is used, the second opening is ≤980℃, the finish rolling temperature is 800-900℃, and the red temperature is increased to 660-700℃, so that the strength is improved and the higher elongation is still maintained.

2. The low alloy single-rolled steel plate production method for cold spinning processing according to claim 1, characterized in that: in the step (1), the blank composition includes, in terms of mass percentage: C: 0.09, Mn: 1.46, P: 0.012, S: 0.003, Si: 0.21, Nb: 0.026, Cr: 0.16, Ti: 0.

014.

3. The low alloy single-rolled steel plate production method for cold spinning processing according to claim 1 or 2, characterized in that: in the step (2), the drawing speed is 1.1 m / min, the electromagnetic stirring process is used, the current is 180 A, and the frequency is 6 Hz.

4. The low alloy single-rolled steel plate production method for cold spinning processing according to claim 1 or 2, characterized in that: in the step (3), 220 mm section blank is used, the heating temperature is 1230℃, and the heating time is 1.0 min / mm.

5. The low alloy single-rolled steel plate production method for cold spinning processing according to claim 1 or 2, characterized in that: in the step (4), the finish rolling temperature is 952℃, the finish rolling temperature is 868℃, the water inlet temperature is 804℃, and the red temperature is 677℃. ​ ​ ​ ​ ​ ​ ​ ​

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