Process setting method for cold-rolled strip continuous annealing heating furnace

Abstract

This invention discloses a process setting method for a continuous annealing furnace for cold-rolled strip steel, comprising the following steps: monitoring and correcting the tracking data of the cold-rolling production line; when the head of a new coil of strip steel reaches 2000m before the continuous annealing furnace, establishing a temperature setting equation for the front and rear specifications of the strip steel based on the thickness of the strip steel in the furnace and the new coil of strip steel, the target heating temperature of the soaking zone, and the optimal operating speed; calculating the transition temperature of the new coil of strip steel in the heating zone and the soaking zone; when the head of the new coil of strip steel reaches 100m before the continuous annealing furnace, pre-setting the transition speed according to the specification parameters of the new coil of strip steel, thus completing the process setting of the transition temperature and transition speed of the new coil of strip steel; the beneficial effects of this invention are: it can achieve a smooth temperature transition when producing strip steel products of different specifications in the continuous annealing furnace, avoid the strip steel temperature from exceeding the target process range, reduce the strip steel process non-compliance length, and improve the production efficiency and product qualification rate of strip steel.

Description

Technical Field

[0001] This invention relates to the technical field of production control for cold-rolled strip continuous annealing, and specifically to a process setting method for a heating furnace for cold-rolled strip continuous annealing. Background Technology

[0002] The process setting of the continuous annealing furnace in the cold rolling continuous annealing unit is an important control link to ensure the quality of strip steel products and improve product production efficiency. The main areas inside the continuous annealing furnace are divided into eight zones: furnace preheating zone (JPF), heating zone (RTF), soaking zone (SF), slow cooling zone (SCS), fast cooling zone (FC), over-aging zone 1 (OAS1), over-aging zone 2 (OAS2), and final cooling zone (FCS). Continuous annealing furnaces can be divided into vertical and horizontal types, and according to the process, they can be divided into continuous annealing, galvanizing, and aluminizing. The difference lies in the open flame setting of the heating section and the over-aging section, which corresponds to different heat treatment processes. According to the set strip temperature curve, the continuous annealing furnace performs different heat treatments on the cooled strip after surface cleaning, thereby controlling the strip performance. During the production process, the annealing temperature or the strip running speed directly affects the product quality and output. At the same time, unreasonable annealing temperature and speed parameters can lead to strip shape problems, and in severe cases, production accidents such as strip deviation and strip jamming may occur. Therefore, the control of annealing temperature and strip running speed is crucial for continuous annealing furnaces.

[0003] During the production process, the difficulty in controlling the temperature and speed of the continuous annealing furnace lies in how to set the transition temperature and speed when switching between different steel grades. Inappropriate process parameters can lead to the strip temperature exceeding the limit, unqualified product quality, low production efficiency, and even equipment damage and production line shutdown, resulting in huge economic losses.

[0004] In the existing control process of cold-rolled strip continuous annealing heating furnaces and production lines, there is an urgent need for a process setting method that can prevent the temperature of strip in the continuous annealing heating furnace from not meeting the standard while ensuring the strip heating system and production rhythm. Summary of the Invention

[0005] The purpose of this invention is to provide a process setting method for a continuous annealing furnace for cold-rolled strip steel, which can achieve a stable temperature transition when producing strip steel products of different specifications in the continuous annealing furnace, avoid the strip steel temperature from exceeding the target process range, reduce the strip steel process non-compliance length, and improve the production efficiency and product qualification rate of strip steel.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A process setting method for a continuous annealing furnace for cold-rolled strip steel includes the following steps:

[0008] Step 1: Monitor and correct the tracking data of the cold rolling production line. Use the tensioning roll in front of the continuous annealing furnace to correct the tracking data. The deviation between the tracking signal detection position and the strip head position should be less than 0.1m.

[0009] Step Two: When the head of a new strip reaches 2000m before the continuous annealing furnace, establish the temperature setting equations for the preceding and following specifications of the strip. Based on these equations, set the transition temperature. The preceding and following specification temperature setting equations are as follows:

[0010]

[0011]

[0012] In the formula, T1 is the target soaking temperature of the strip in the furnace, in °C; T2 is the target soaking temperature of the new coil of strip, in °C; t1 is the thickness of the strip in the furnace, in mm; t2 is the thickness of the new coil of strip, in mm; S1 is the optimal running speed of the strip in the furnace, in m / min; S2 is the optimal running speed of the new coil of strip, in m / min; T RTF The transition temperature of a new coil of strip steel entering the heating section of the furnace, expressed in °C (T). SF The transition temperature of a new coil of strip steel entering the soaking zone of the furnace, expressed in °C.

[0013] The optimal running speed S of the strip is calculated based on different specifications of the strip. The equation for calculating the optimal running speed S of the strip is as follows:

[0014] S = 180*(2-t) + 0.2*(1550-w),

[0015] In the formula, t is the thickness of the strip steel in mm, and w is the width of the strip steel in mm;

[0016] Step 3: Using the on-site control PLC, logical judgments are made based on the physical positions of each area in the continuous annealing furnace and the position of the strip head. When the head of a new coil of strip reaches the position 100m before the continuous annealing furnace, the transition speed is preset according to the specifications of the new coil of strip. The position 100m after the strip in the furnace is adjusted from S1 to S2 at a speed of 5m / s. The areas in the continuous annealing furnace include the preheating section, heating section, soaking section, slow cooling section, fast cooling section, over-aging section 1, over-aging section 2, and final cooling section.

[0017] Step 4: When the head of the new strip reaches the heating furnace position, T RTF =T2,T SF =T2.

[0018] Step 5: Jump to Step 1 to complete the process settings for the transition temperature and transition speed of the new coil of strip steel.

[0019] The beneficial effects of this invention are as follows: Based on the process parameters of the new coil of strip steel to be produced, this method can reasonably determine and set the optimal transition temperature and transition speed of the heating section and the soaking end in the continuous annealing furnace, thereby effectively reducing the probability of strip steel deviating in the continuous annealing furnace. Under the complex situation where the annealing temperature of the target soaking section and the strip steel specification parameters change simultaneously, it can effectively control the smooth transition of strip steel temperature, avoid strip steel temperature exceeding the target process range, reduce the length of strip steel process non-compliance, and ensure the optimal running speed of the corresponding strip steel without reducing the strip steel temperature, thereby ensuring the production efficiency of the production line and improving the production efficiency and product qualification rate of strip steel. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be described below.

[0021] Taking the production process as an example, the thickness of the strip in the furnace is 0.5mm, the width is 1366mm, the target heating temperature of the soaking zone is 780℃, and the thickness of the new coil of strip is 0.6mm, the width is 1300mm, and the target heating temperature of the soaking zone is 800℃.

[0022] This application provides a process setting method for a continuous annealing furnace for cold-rolled strip steel, the process setting method including the following steps:

[0023] Step 1: Monitor and correct the tracking data of the cold rolling production line. Use the tensioning roll in front of the continuous annealing furnace to correct the tracking data. The deviation between the tracking signal detection position and the strip head position is 0.02m.

[0024] Step Two: When the head of a new strip reaches 2000m before the continuous annealing furnace, establish the temperature setting equations for the preceding and following specifications of the strip. Based on these equations, set the transition temperature. The specific setting process is as follows:

[0025] S1=180*(2-0.5)+0.2*(1550-1366)=270+36.8=306.8,

[0026] S2=180*(2-0.6)+0.2*(1550-1300)=252+50=302,

[0027]

[0028]

[0029] Step 3: Using the on-site control PLC, logical judgments are made based on the physical positions of each area in the continuous annealing furnace and the position of the strip head. When the head of a new coil of strip reaches the position 100m before the continuous annealing furnace, the transition speed is preset according to the specifications of the new coil of strip. The position 100m after the strip in the furnace is adjusted from S1 to S2 at a speed of 5m / s. The areas in the continuous annealing furnace include the preheating section, heating section, soaking section, slow cooling section, fast cooling section, over-aging section 1, over-aging section 2, and final cooling section.

[0030] Step 4: When the head of the new strip reaches the heating furnace position, T RTF =800, T SF =800.

[0031] Step 5: Jump to Step 1 to complete the process settings for the transition temperature and transition speed of the new coil of strip steel.

Claims

1. A process setting method for a cold-rolled strip continuous annealing furnace, characterized by: Includes the following steps: Step 1: Monitor and correct the tracking data of the cold rolling production line. Use the tensioning roll in front of the continuous annealing furnace to correct the tracking data. The deviation between the tracking signal detection position and the strip head position should be less than 0.1m. Step Two: When the head of a new strip reaches 2000m before the continuous annealing furnace, establish the temperature setting equations for the preceding and following specifications of the strip. Based on these equations, set the transition temperature. The preceding and following specification temperature setting equations are as follows: ， ， In the formula, The target soaking temperature for the strip in the furnace, expressed in °C. The target soaking and annealing temperature for the new coil of strip steel, in °C. This refers to the thickness of the strip steel inside the furnace, in mm. The thickness of the new coil of strip steel, in mm. The optimal running speed of the strip in the furnace, expressed in m / min. The optimal running speed for a new coil of strip steel, expressed in m / min. The transition temperature of the furnace heating section before a new coil of strip enters the furnace, expressed in °C. The transition temperature of the soaking zone in the furnace before a new coil of strip enters the heating furnace, expressed in °C. Among them, the optimal running speed of the strip is calculated based on different specifications of the strip. The optimal running speed of the strip steel The calculation equation is as follows: ， In the formula, The thickness of the strip is in mm. The width of the strip is in mm. Step 3: Using the on-site control PLC, logical judgments are made based on the physical positions of each area within the continuous annealing furnace and the position of the strip head. When the head of a new coil of strip reaches the position 100m before the continuous annealing furnace, a pre-set transition speed is implemented based on the specifications of the new coil of strip. The tail 100m of the strip inside the furnace is then moved at a speed of 5m / s. Adjust to The continuous annealing furnace includes preheating section, heating section, soaking section, slow cooling section, rapid cooling section, over-aging section 1, over-aging section 2, and final cooling section. Step 4: When the head of the new coil of strip reaches the heating furnace position, , ; Step 5: Jump to Step 1 to complete the process settings for the transition temperature and transition speed of the new coil of strip steel.

Images