Pay attention to safety when heat treating magnesium alloy

Due to the flammable nature of magnesium alloys, incorrect heat treatment operations will not only affect the quality of magnesium alloys, but may also cause fires, so the safety of magnesium alloy heat treatment must be taken seriously.

 
Before heating magnesium alloys, the instruments must be accurately calibrated and the electrical equipment checked. Before loading the furnace, the burrs, debris, oil stains, other pollutants, and water on the surface of the magnesium alloy must be cleaned, and the magnesium alloy and the inside of the furnace must be kept clean and dry.
Magnesium alloys should not have sharp edges and corners, and it is absolutely forbidden to heat them in a nitrate bath to prevent explosions.

 
The production workshop must be equipped with fire-proof equipment, and only products of the same magnesium alloy are allowed to be loaded into the furnace, and the heat treatment process specifications of magnesium alloys must be strictly followed.
When magnesium alloy burns in the furnace due to equipment failure, control instrument failure or operation error, the power supply should be cut off immediately, the fan should be turned off, and the supply of protective gas should be stopped.

 
If the heat input of the heat treatment furnace does not increase, but the furnace temperature rises rapidly and white smoke comes out of the furnace, it means that the magnesium alloy in the furnace has been burned violently. It is absolutely forbidden to use water to extinguish the fire.
After the magnesium alloy burns, all power supplies, fuel and protective gas delivery should be cut off immediately to extinguish the small flame in the furnace of the magnesium alloy due to lack of oxygen.

 
If the flame continues to burn, the following fire extinguishing methods can be adopted according to the characteristics of the flame:
1, if the fire is not big and the burning magnesium alloy is easy to be safely removed from the furnace, the magnesium alloy should be transferred to a safe place and covered with a special magnesium alloy fire extinguishing agent.

 
2, if it is neither easy to approach nor safe to remove the magnesium alloy, the fire extinguishing agent can be sprayed into the furnace with a pump to cover the burning magnesium alloy.

 
3. If the above two methods cannot extinguish the fire in time, bottled BF3 or BCl3 gas can be used to extinguish the fire. High-pressure BF3 gas is passed from the gas cylinder into the furnace until the fire is extinguished, and the furnace door is opened after the furnace temperature drops below 370 ℃ . BCl3 gas is passed into the furnace in the same way. In order to ensure the gas supply, it is best to heat the gas cylinder. Bcl3 reacts with the burning magnesium to generate thick fog surrounding the magnesium alloy. The purpose of fire extinguishing can be achieved.

 
4. If the magnesium alloy has been burning for a long time and there is a lot of liquid metal on the bottom of the furnace, then the above two gases cannot completely extinguish the flame, but they will have the effect of inhibiting and slowing down the combustion. They can be used in combination with other fire extinguishing agents to achieve the purpose of fire extinguishing. The fire extinguishing agents that can be selected include dry sand, asbestos cloth, solvents for magnesium alloy smelting, etc.

 
In addition to the conventional personal safety protection measures when extinguishing aluminum-magnesium alloy fires, tinted glasses should also be worn to prevent the strong white light emitted by the burning magnesium alloy from hurting the eyes.