Why You Should Cryogenically Treat Your Industrial Knife or Blade

Durable, long-lasting blades are a necessity in food processing, packaging and other industrial applications. Investing in high-quality blades is vital to your operation’s productivity and overall bottom line.

Cryogenic treatment is a common process designed to enhance the performance of metal blades. Extreme deep freezing increases the service life of knives by improving their resistance to wear. As a one-time treatment, freezing knife blades makes them more durable and less prone to chipping and fracturing under stress. Learn more about the advantages of cryogenically treated industrial knives that can stand up to tough conditions.

About Metal Hardening Treatments

Metal manufacturing, particularly in precision toolings like knives and blades, is a complex process. It requires expert-level skill to produce metal products that will maintain their hardness, strength and overall productive life under many different conditions of industrial stress. During the manufacturing process, a standard way to improve the hardness of metals, like iron, steel, aluminum or copper, is to expose the material to extreme temperatures. Exposure to extreme heat, also called heat treatment, fundamentally alters the material at its atomic level.

The metal moves from a solid to a liquid state under high heat and then back to a solid state during its rapid cool-down period. These transitions cause the material’s atoms to expand and rearrange themselves into a crystal structure. Depending on the material, this crystal structure may take on variations of cube shapes, meaning that the atoms are now ordered in a sturdy, stable and durable arrangement. As an analogy, consider the stability differences between a wooden box and a beach ball.

Because countless of these newly reshaped molecules make up the overall metal itself, the metal now retains these extra-durable mechanical properties of its new atomic arrangement. Metal tool manufacturers follow different steps and procedures within this overall framework to achieve the precise amount of durability and hardness they desire — whether that’s at the surface level or through the material’s cross-section.

However, heat treatment isn’t the only type of temperature hardening that metal can undergo to achieve improved durability. Plunging metals into extremely freezing cold conditions can also produce a similar yet unique effect.

What Is Cryogenic Treatment?

Cryogenic treatment of metals is a process where metals are deliberately exposed to freezing temperatures for a prolonged and controlled period. During manufacturing, the metal is first exposed to heat to move from a solid to a liquid state. Then, during the cryogenic treatment phase, liquid nitrogen is applied to the material. Finally, it gets preserved at temperatures down to minus 300 degrees Fahrenheit. Depending on the process, the metal may be held at this temperature for 24 hours or longer. By comparison, the traditional heat-treating process allows the metal to cool at room temperature but doesn’t ever move the metal into freezing temperatures.

Depending on the provider’s process, the metal can then undergo a second round of heating or cryogenic freezing to stabilize the material’s new structure. It may also undergo more than two rounds of this heat-freeze or heat-cool procedure using liquid nitrogen or not.

The primary advantage that’s unique to cryogenic freezing is that the metal’s atoms rearrange in such a way that it increases the metal’s martensite structure and decreases its austenite structure. Martensite is a hard crystalline structure, while austenite structures provide more softness and ductility, meaning its ability to bend under tensile stress without breaking.

Because of this unique arrangement that metal undergoes during liquid nitrogen freezing, cryogenic treatment has many benefits for knife and blade manufacturing and maintenance.

The cryogenic treatment process was first developed over 100 years ago. It wasn’t until the mid-20th century that the technology improved, and it became more widely offered for commercial uses. Cryogenic treatment goes by many other names, including cryogenic tempering, cryogenic hardening and deep cryogenic treatment (DCT), which usually indicates that the process uses temperatures below 300 degrees Fahrenheit.

Benefits of Cryogenically Treating Your Blades and Knives

Cryogenically treating industrial knives and blades is a proven process for improving durability, reducing wear, increasing the service life of blades and improving overall productivity and cost-effectiveness for business operations. By choosing to invest in cryogenically treated blades or knives, you’ll benefit from longer-lasting blades that require less maintenance and cause less downtime to your operations.

Here are a few of the many reasons why cryogenically treated industrial knives and blades are a good option for your business.

1. Increases Resistance to Wear and Tear

The primary benefit of cryogenically freezing knife blades is that it increases the blades’ resistance to wear and tear. In industrial settings, maintaining and improving productivity are the primary goals. Knives and blades need to undergo and repeated use, often under high-impact and severe conditions. They need to maintain their shape, sharpness or strength.

Metal becomes harder through the cryogenic process and can then stand up to significant and repetitive use for much longer. With increased wear-resistance, blades continue to keep their sharp edge. Business operators will benefit from cryogenic treatment ultimately because less wear over time leads to an increase in the blade’s usable life. Business owners go through fewer blade replacements and get more value from their initial investment.

2. Reduces Susceptibility to Stress

Industrial knives undergo repetitive, high-stress use, so products need to withstand these tough conditions. One of the primary reasons why a blade can’t withstand extreme, regular use is because of the lack of uniformity in the metal’s composition at the molecular level. Metals that weren’t properly hardened tend to crack, break and fail under pressure due to their weak points.

Cryogenic freezing is a process designed to address this concern. When metal is heated and then rapidly plunged into deep cryogenic conditions, it promotes a more uniform composition in the final product. The result is the knife will be less likely to fail under repeated, heavy use due to fewer stress lines in the blade.

3. Improves Water, Rust and Oxidation Resistance

Ferrous metals, like cast iron, stainless steel or steel alloys, and non-ferrous metals, like aluminum or copper, are both prone to oxidation, which increases wear. Oxidation is a chemical reaction that takes place on the metal’s surface when oxygen is present. Over time, oxidation corrodes the metal.

All metals undergo oxidation to an extent, but certain manufacturing processes can delay oxidation and extend the usable service life of metals, such as those used for industrial knives and blades. Cryogenic treatment is a process that doesn’t promote oxidation of the metal’s surface, meaning it doesn’t discolor and succumb to oxidation-caused wear. Conversely, some heat treatments can cause oxidation on the metal’s surfaces, negating some of the short-term wear-resistance benefits that cold-tempering provides.

4. Provides a Permanent Hardening Treatment

Cryogenically treating knives and blades is a one-time procedure done to metal products during manufacturing or servicing. Because the process changes the material at the atomic level, the metal’s properties have been permanently changed. There’s no way for the metal to lose its increased durability, wear-resistance and stress relief once it’s undergone cryogenic treatment unless it were to undergo another deliberate temper treatment afterward.

As a result, knives and blades that have been treated cryogenically will retain their improved hardness, even after repeated use. All the benefits of cryogenic freezing stay with the blades permanently, ensuring a long usable life of strength and durability. As you sharpen, polish and maintain your blades, the knives or blades will maintain the durability and wear-resistance from cryogenic freezing.

5. Mitigates Safety Risks

A high-quality blade is a safe blade. On the other hand, a dull blade poses a severe risk to workers. Using dull blades requires more force and increases the risk of the blade pinching the material, getting stalled during cutting or even kicking back material when a clean cut can’t be made.

Cryogenic treatment for industrial knives maintains the blade’s sharpness longer due to the reduced wear. Additionally, cryogenic treatment of metals creates a micro-smooth finish and reduces the amount of friction a blade experiences during cutting. The result is a safer product that will pose less risk to workers and reduce workplace injuries.

6. Improves Sharpening

Another significant benefit of investing in cryogenically treated industrial knives is the resulting improved sharpness of the blade. Because cryogenic freezing causes a more uniform atomic distribution in the metal itself, the process helps to eliminate microvoids and other imperfections in the metal. These weak points can cause the metal to fail after repeated use, as the blade will start to chip and break at these locations.

Under cryogenic treatment, these gaps close up, and the material becomes denser. With a more uniform grain structure after cryogenic treatment, knives and blades will maintain more consistent sharpening and keep their edge longer. A sharper edge speeds up the cutting process, ultimately improving operational productivity and reducing downtime.

7. Extends the Life of Knives

All business operators want to know that the investment they make in their tools is going to pay off. In industries where tools undergo repeated and extreme use, operators can’t afford to have their blades become distorted or dull without getting a full service life out of them.

The cryogenic treatment process increases the usable life of blades because it lowers the amount they wear over time. With blades that stay stronger longer, operators spend less time and money ensuring their industrial knives or blades go through proper maintenance cycles. With fewer maintenance cycles, the business maintains high levels of efficiency and experiences less non-productive downtime.

Additionally, cryogenically treated blades offer a smooth finish, need less polishing and grinding and require less material removal. You can easily restore the blade’s sharp edge with little maintenance.

8. Compatible With Various Metals

Cryogenic hardening is a versatile process that’s compatible with many different metals, including materials commonly used to make knives and blades, such as carbide stainless steel and various alloys. Cryogenic freezing is also beneficial to other ferrous and non-ferrous metals like cast iron, magnesium, copper and aluminum.

Cryogenic Treatment Process

Most manufactured metal tools undergo a hardening treatment process, conventionally done through heat treatment. Cryogenic treatment is an extension of this usual process, following similar steps but adding in the controlled application of a cryogenic fluid, like liquid nitrogen. The cryogenic treatment process can vary depending on a few factors:

  • The type of workpiece being treated
  • The type of metal being treated, including its alloy composition
  • The applications of the tool
  • The cryogenic treatment provider, which all use proprietary procedures

The cryogenic treatment process is computer-controlled, meaning it’s a precise, timed procedure that can be tailored to each product type. While each provider’s unique process will vary, a general step-by-step process is described below.

  1. Raise the temperature during heat treatment: During treatment, the material is first be brought from room temperature up to plus 200 degrees Fahrenheit or more. This step primes the material at a molecular level to form a crystalline structure. After heat treatment, the material is brought back to room temperature to cool.
  2. Drop the temperature during cryogenic treatment: After the material has been resting at room temperature, it’s then brought down to minus 300-310 degrees Fahrenheit. Reducing material to this extreme deep freeze transforms ductile retained austenite (RA) into martensite structures, which are the crystalline arrangements that give metals their desired hardness.
  3. Raise the temperature again to stabilize the material: After cryogenic treatment, some providers will then elevate the temperature yet again, this time to plus 300 degrees Fahrenheit, and even reaching plus 700 degrees Fahrenheit in some cases. This last fluctuation in temperature is meant to solidify the martensite structures that formed in the cryogenic phase.

After the last increase in temperature, the material is left to cool at room temperature, finalizing the process. The amount of time that a material spends under any given temperature is determined by the thickness of the material. Thicker materials take longer for the cold or the heat to penetrate the core. Using the material’s cross-sectional thickness, technicians calculate the required time in British Thermal Units (BTUs) per hour, and that’s how long the material spends under each temperature condition.

Choose York Saw & Knife for Your Knife and Blade Needs

Having durable, long-lasting blades that can withstand repeated use under stressful, high-impact conditions is imperative to your operation. You need trusted and reliable products manufactured under rigorous standards that are up to the task. York Saw & Knife specializes in custom machine knives and blades made for precision.

To learn more about custom industrial knives and blades for your operation, request a free quote today. For more information about the York Saw & Knife process and how we can help, contact us online or give us a call at 1-800-233-1969.