Cold rolling silicon steel sheet stress relief annealing process

- Aug 02, 2019-

1. The silicon steel sheet to be annealed is placed in the iron box (according to the size of the silicon steel sheet, it is better not to exceed three layers for the packing). The rack is covered with a cover plate slightly smaller than the iron box (preferably The silicon steel sheet material is made), hoisted into the furnace, and the furnace cover is locked.

2. Install three thermocouples of Dahua Watch on the furnace body, install the chimney, and open the exhaust valve.

3. Check the voltage, current and meter of the electrical cabinet. Install the recording paper of the Dahua Watch and check the normal paper feed of the recording paper (first turn on the power switch).

4. Set the initial temperature of the temperature control meter to 400 °C, check whether the currents of the power meter are consistent. After ensuring the adjustment is consistent, turn on the heating switch to heat.

5. Check the normality of the meter in the electric house and adjust the power of the furnace.

6. Connect the nitrogen gas, check for leaks, and check the normal supply of circulating water.

7. When the temperature rises to 400 ° C, open the nitrogen nitrogen valve and inject 100-200 ml of nitrogen. At this time, open the valve of the circulating water.

8. When the temperature is determined to rise to 400 °C, the temperature is constant, the temperature is about 1 hour, and the temperature of the Dahua Watch is also about 400 °C (the exhaust gas is not a lot).

9. After the heat preservation is completed, set the temperature control table to 500 °C and heat it. Pay attention to whether the current meter is in the same condition and have problems in time.

10. When the temperature rises to 500 °C, the temperature is kept for about 45 minutes. At this time, whether there is any change in the furnace body, whether there is air leakage, and whether the circulating water supply is normal.

XI. After the constant temperature is completed, set the temperature control table to 600 °C for heating. Increase the nitrogen pressure regulating valve and inject 200-400 ml of nitrogen gas. At this time, the exhaust gas is more.

12. When the temperature rises to 600 °C, the temperature is about 45 minutes. At this time, see if the voltage is normal.

Thirteen, finally set the temperature control table to 680 ° C -750 ° C (depending on the silicon steel sheet material, cold rolled non-oriented silicon steel sheet low grade domestic B50A600, 50W600, 50AW600, 50WW540 below the general annealing temperature is around 680 ° C, imported The same material can be properly +20 ° C, the non-oriented high grade general annealing temperature is about 750 ° C. Cold-rolled oriented silicon steel sheet generally annealing temperature is about 820 ° C). Nitrogen can be opened larger, or 400 ml of nitrogen can be maintained, and the exhaust gas is more.

14. After the temperature rises to the set temperature, the constant temperature time should not be less than 2 hours. The Dahua Watch should also be above and below the set temperature. At this time, the exhaust valve can be closed smaller.

Fifteen, after the end, close the exhaust valve (not closed), nitrogen injection in 100-200ml, the circulating water valve can be closed (the outlet valve is always open), turn off the heating switch, power switch.

16. After the inspection is correct, the furnace silicon steel sheet is subjected to the stress-relieving annealing process and enters the natural cooling state. When the furnace temperature drops below 380 ° C (preferably 350 ° C), it can be discharged.