Steel bonded tungsten carbide has high hardness, high strength, high welding technology and excellent mechanical properties of deposited metal. The deposited metal has excellent mechanical properties. But its hardnes after welding is low (around 33HRC), which is easy for simple machining. After aging treatment, the hardness is greatly increased and it even up to SOHRC, which can be used for mold welding and repair.

 

 

This efficient and excellent material has been popularized and applied to cold working dies, but it has not seen many applications in hot working dies. Reason is that the working condition of the hot working die is very bad, it is in contact with the red-hot metal or the non-metal phase and slid relatively when working. That is, it needs the high temperature wear resistance of the mold. In addition, due to frequent heating and cooling in the service process, thermal fatigue is very easy to produce. It is the main failure mode of some metal components that have been subjected to alternating stress for a long time.

 

Actual production and lots of research data indicate that high temperature wear failure and thermal fatigue failure are the most common failure modes of hot working dies. There are two main phases in steel bonded tungsten carbide: the physical and chemical properties of WC (TiC) are different from those of steel matrix, especially the difference of thermal expansion coefficient.

 

Therefore, poor thermal fatigue performance often appears under the action of thermal stress. But the research shows that if the hard phase content of the alloy is moderate, the grain size and shape are good and the steel matrix with high resistance to thermal fatigue, it can still make the alloy have high thermal fatigue resistance.

 

WC particles content in steel bonded tungsten carbide is moderate. The binder steel matrix is a hot working die steel with high mechanical properties at high temperature. Reasonable composition design makes the effect of particle reinforced steel matrix remarkable. Steel bonded tungsten carbide not only has high hardness, high strength and high wear resistance at room temperature, but also exhibits strong wear resistance and thermal fatigue resistance at high temperature. It can be used as cold working die or hot working die.

 

It is suggested that the forging material should be chosen as much as possible when using this alloy. When manufacturing cold moulds, heat treatment technology of tempering at 1000 degree or 180 and 200℃ can be selected. In the hot working dies, we can choose quenching treatment at 1100 degree or so and heat treatment at tempering at 550~600℃.