Five operation steps of gas nitriding furnace

Gas nitriding furnace has the characteristics of low treatment temperature, short treatment time and small deformation of workpiece. Its properties are high fatigue limit and good wear resistance.

1. The gas nitriding furnace before nitriding must be the workpieces that have been normalized or tempered first.

2. First scrub the surface of the workpiece of the gas nitriding furnace with gasoline and alcohol, and there shall be no rust spot, oil stain and dirt.

3. After being installed in the furnace, tighten the furnace cover pressing bolts symmetrically.

4. Connect the water inlet of furnace tank and furnace cover with cooling water for circulating water cooling. The lower end of the cooling water of the pipe on the gas nitriding furnace cover is water inlet, the upper end is water outlet, the furnace tank is separately water inlet and separately drained, all water pipes of the gas nitriding furnace cover can be connected in series according to the principle of low water inlet and high water outlet, and one water inlet and one water outlet are used for drainage.

5. Before heating up the gas nitriding furnace, nitrogen shall be sent for exhaust, and the flow shall be more than twice as large as that in use.

After exhausting for 10 minutes, set the temperature control instrument to 150 ℃, turn the automatic heating switch to on, heat the exhaust side of the gas nitriding furnace to 150 ℃ and keep exhausting for 2 hours, then set the temperature control instrument to 530 ℃, reduce the ammonia flow rate, keep the positive pressure in the furnace, and there is a smaller pressure in the exhaust port. When the furnace temperature rises to 530 ℃, the constant temperature constant flow nitriding for 3-20 hours, and then increase the ammonia pressure, Let the exhaust gas maintain a moderate pressure, nitriding for 4-70h, then reduce the ammonia pressure, denitrification for 1-2h, cut off the power supply, give a small amount of ammonia to maintain a positive pressure in the furnace, and stop the ammonia supply and discharge until the furnace temperature drops below 150 ℃.