The perfect knife steel for robots of the future
The meat industry has long been faced with a choice between two types of knife steel for its machines and robots. So far, the choice has been between steel that is rust-resistant yet “soft” and steel that is hard and yet prone to rust. The Swedish steel producer Uddeholm AB has joined forces with the Danish Meat Research Institute to develop a rustresistant material that combines the best properties of both types.

Less maintenance

The new metal alloy can be used to produce knife steel that can withstand machine washing and yet retain its sharpness. The knife can remain in a machine for longer without needing to be sharpened, which means less time spent on maintenance.

The new knife steel can also withstand moist acidic and alkaline environments without surface corrosion and is sufficiently hard for the knife edge to retain its sharpness for longer.

A set of circular knives made from the new steel has already been tested in a machine designed for loosening heart plucks. After a series of tests, the results show that the new steel has no drawbacks and that the working life of the knives is one and a half times longer than that of knives made from ordinary knife steel.

Expensive but better

Since the knives used in the slaughterhouse robots tend to be expensive to produce, the meat industry has long been searching for a more durable type of steel. The new knives are more hard-wearing and corrosion-resistant and can be tempered to achieve a hardness that far exceeds that of standard steel.

Although the cost of the new steel is approximately four to five times higher than that of standard steel because the price of steel often accounts for only a small proportion of the total price of a knife, the new knife steel has a promising future in the slaughterhouse industry. This is particularly so because it is expensive to stop production whenever a knife has become blunt and needs replacing.

Ready for production

Two years ago, Uddeholm started to look for areas to test their new steel and eventually reached a point where they could produce a type of steel that came close to meeting the Danish meat industry’s requirements for knife steel.

The new steel, Vanax 75, is produced by powder metallurgy methods and contains high levels of chromium and vanadium. In practice, this means that the material has a corrosion resistance close to that of stainless steel AISI 316. It can be tempered to achieve a hardness of 60 HRC.

The wear resistance of the new steel is far greater than that of AISI 316. In the powder metallurgy production process, the carbides (compounds composed of carbon and an element such as V, Mo, W, Cr), which provide wear resistance, are evenly distributed throughout the entire matrix. This makes it possible to combine wear resistance and toughness.

The material for knife production is now ready for production.

For further details, please contact Carsten Jensen cj@danishmeat.dk