The ferro-tungsten alloy series (70%-80% tungsten content) is an alloy composed of tungsten and iron, used as an alloy additive for steelmaking. Commonly used tungsten-iron alloys have two kinds of tungsten content 70% and 80%.
The Smelting Method Of Iron Alloy Containing Tungsten
The method of smelting ferro tungsten alloy is to heat the charge to a certain temperature area; then add a certain amount of tungsten concentrate and reducing agent mixture. The steps are:
- First add 100-110% of the theoretical amount of steel or iron into the reaction tank in the electric furnace and heat it to 1540-1590°C to melt it;
- Then add the mixture of tungsten concentrate, aluminum pellets and sodium nitrate mixed in a certain proportion into the tank at a speed of 70-110 kg/min·m↑; during the feeding, continue to heat to increase the furnace temperature to 2500-3000°C.
- After feeding, continue to add heat to the melt and maintain the slag temperature above its melting point for 7-20 minutes;
- Stop heating and let the melt in the furnace cool to a solid state and then come out of the furnace.
The Classification Of Iron Alloy Containing Tungsten
Tungsten and iron are mainly composed of iron alloys. It also contains impurities such as manganese, silicon, carbon, phosphorus, sulfur, copper, tin, etc., and is an alloying agent for steelmaking. According to the different tungsten content, ferro-tungsten is divided into FeW75 (containing W70%～80%, C≤0.20%, P≤0.04%, S≤0.08%, Si≤0.5%, Mn≤0.25%) and FeW80 (containing W70%～80%) W75.0%～85.0%, C≤0.20%, P≤O.04%, S≤0.08%, Si≤0.7% and Mn≤0.25%).
The Physical State Of Iron Alloy Containing Tungsten
The ferro-tungsten is in the shape of a lump with a lumpiness ranging from 10 to 130mm. The amount of fragments smaller than 10×10mm should not exceed 5% of the total weight of the batch. The maximum size of individual lumpiness in one direction is 150mm. The surface of the tungsten iron block should be smooth and clean, and there should be no significant non-metallic inclusions and rust spots on the section and surface.