What Is Cryogenic Tempering?
Making materials stronger by cryogenic tempering is something that has experts divided.
Studies show that cryogenic tempering does little to make the materials stronger, but the process does increase the materials resistance to wear and tear. It’s achieved by improving dimensional or microstructure stability.
Depending on the clients specification, the materials could be kept in a supercooled state for up to 24 hours.
In some cases it might be treated to a second round of treatment. A traditional heat treating production would let the materials cool to room temperature before moving on to a cleaning process. The cryogenic tempering process forces the molecules inside to revert to a more compact and organized state.
What Benefits Does Cryogenic Tempering Have?
Leaving the materials in this state has a variety of benefits:
- Increased Resistance to Wear and Tear
- Increased Stress Failure Results
- Oxidisation and Rust Resistance
- Extends Lifetime of end Products
What Does All That Mean?
Some of these concepts are really quite advanced so I’ll try to break it down. Let’s understand how cold things need to be in order to get the process right though.
Once the material has been heated up and shaped it goes through a few processes before it’s cooled using liquid nitrogen.
Once the product has been shaped and formed, it is heated to 240 degrees Fahrenheit/ 130 degrees Celsius. The molecules within the material start to move around once the temperature has been reached (Depending on the materials used i.e mix of steel temperatures may vary) and they start to form a crystalline pattern, it is then cooled normally back to room temperature.
In order to stabilise the molecules resting place it’s the cryogenic tempering process really begins. It’s succumbed to minus 300-330 degrees Fahrenheit/ -200 degrees Centigrade. Taking the temperature down to this level of deep freeze changes ductile retained austenite (RA) into martensite structures.
It’s the martensite structures that make cryogenic tempering the process that it is.
In some cases the process will be repeated but this will usually add to to the cost of the end product.
More On The Benefits
Increasing the materials resistance to wear and tear is a good thing. In the knife making industry it’s something that customers want.
As a manufacturer, if you can guarantee longer lasting products, you can increase the price, the cryogenic tempering process will likely add some cost onto the final price but if you want to make money you have to spend money. Making better materials should be a companies foremost focus.
Increased wear and tear means a knife’s edge keeps its edge sharper for longer.
Longer Shelf Life
The process is also excellent for rust and oxidation resistance. Most knife making brands like to use Stainless Steel mixes as it’s a good, durable product. Steel is susceptible to rust but with cryogenic tempering, the oxidation process is delayed extending the lifetime of the knife.
Not only that but add in the added durability this also impacts the total shelf life of the product in question. Being a better, harder blade, the routine maintenance of the knives doesn’t have to be executed as often, saving time and money on extra costs such as sharpener blocks or whet stones.
Uniform Atom Distribution Means Sharper Knives
When anything gets heated up, the atoms inside it move faster (Fun fact, temperature is actually a measurement of how fast atoms move, it’s specifically based on how hot something is) when cryogenic tempering takes place the atoms take a more uniformed distribution.
Almost in the same way a honeycomb atoms move together to provide one of nature’s toughest structures, the atoms structured when this process takes place makes a harder more resistant material.