faq cryogenic treatment

What types of services do you offer?

For over thirty years, Controlled Thermal Processing, Inc. has been a leader in Deep Cryogenic Treatment and thermal processing of metals and specialized plastics.

Our multiple locations allow us to offer these services coast to coast:

  • Deep Cryogenic Treatment of metals and plastics for optimal performance
  • Metallurgical consulting to improve tool use and efficiency
  • Partnering with manufacturers to produce and market superior products
  • Cryogenic equipment sales
  • Liquid Helium processing at temperatures down to -450ºF
  • Micro-Polishing of components

What industries benefit the most from your services?

We are able to treat a broad spectrum of metals and specialized plastics, from brake rotors to machine components for large-scale factories. Our services are most often applied to the following industries:

  • Aerospace
  • Marine
  • Transportation
  • Industrial
  • Electronics & Audio

Contact us today to see how CTP can help your business!

Where are your facilities located?

We have TWO  locations across the United States for faster service and more convenient shipping.

  • West Coast Facility | Torrance, CA
  • Midwest Facility | Marion, IA

How does Deep Cryogenic Treatment work?

At precise temperatures, the crystalline structure of metals and some plastics undergo changes. As the temperature drops, the movement of the atoms in the material begins to slow. The spaces between atoms begin to contract with this lower momentum.

The result of Deep Cryogenic Treatment (DCT) is a refinement of the structure into a more uniform and durable formation. As the material is brought slowly back to room temperature, the speed of the particles increases, but with far fewer gaps and a more perfect crystalline alignment.

At CTP, our experts understand the field of cryogenics better than anyone in the business, using state-of-the-art equipment and advanced scientific methods to improve the strength, quality, and lifespan of metals and specialized plastics.

For more information about how cryogenic processing works, visit our Cryogenics Explained page.

Can Deep Cryogenic Treatment make metals brittle?

While many metals and plastics do become brittle when brought down to extremely low temperatures, the brittleness dissipates as the material returns to ambient temperature and is ultimately not a factor in the treated part.

The exception is in situations in which there is significant retained austenite that transforms to martensite. The tempering cycle at the end of cryogenic process tempers the martensitic structure much like the quench and tempering when hardening steel.

Does the nitrogen used in the process pollute the air?

No, the liquid nitrogen used during our process does not pollute the atmosphere. Liquid nitrogen is made by cooling atmospheric air down below the temperature of below -320°F(-196°C). By using liquid nitrogen, it is just returns it to the atmosphere — which is about 78% nitrogen.

It is worth noting that, if you release enough nitrogen in a closed room you will dilute the oxygen so it is important to use adequate ventilation.

What is the difference between cryogenic processing and cold treatment?

Cold treatment is performed by heat treaters to convert retained austenite to martensite. It usually takes place at about -140°F (-96°C). There is no specific profile to follow, and cold treatment does not seem to have any effect on cast iron or aluminum or other metals and plastics. Case studies have shown that cold treatment is far less effective in strengthening metals versus proper cryogenic treatment.

Can I just dip my metal parts in liquid nitrogen?

Research indicates that dipping in liquid nitrogen is successful about 10% of the time. Think of it this way: If you dip a part into liquid nitrogen the surface wants to contract to the size it would be when it is -320°F (-196°C). The inside of the part is still at room temperature and therefore at the size it would be at room temperature. This creates stresses, and the stresses at the surface are there at temperatures where the metal is brittle.  

Many of the effects that Deep Cryogenic Treatment creates take time in specific temperature ranges.  Dipping the part takes the part through those ranges too quickly and those effects do not take place.

Our system of slow cooling eliminates the extreme temperature differentials created by dipping the part or by having a nitrogen spray hit the surface, and controls the temperature of the metal to allow adequate time for the changes in the metals to fully take place.

What is the difference between deep cryogenic processing and cold treatment?

Cold treatment is performed by heat treaters to convert retained austenite to martensite. It usually takes place at about -140°F. There is no specific profile to follow. Cold treatment does not seem to have any effect on cast iron or aluminum. Experiments show that cold treatment is nowhere near as effective as proper deep cryogenic treatment.

Does deep cryogenic processing do more than just convert retained austenite to martensite?

In short, yes, deep cryogenic processing does much more than simply convert retained austenite into martensite. On hardened steels, cold temperatures will induce retained austenite to convert to martensite, but the austenite that is going to convert is usually converted by about -140°F, which is not even into the cryogenic range of about -244°F.

However, deep cryogenic processing causes parts that do not contain retained austenite to exhibit changes. For instance, automotive brake rotors increase their life between two and four times when processed. The microstructure of brake rotors is pearlitic; they contain no austenite.  Resistance welding electrodes made of copper alloys also exhibit significantly increased life and also have no austenitic structure.

What should I do if I’ve lost the vacuum of my cryogenic processing equipment?

Although loss of the vacuum is rare, it can usually be fixed by the same people who fix the dewars that nitrogen is shipped in. These dewars are banged around in loading them into trucks, knocking against other other dewars and equipment on the trucks when road hazards are encountered and then unloaded. If they develope a vacuum leak they are simply fixed, much like you would fix a flat tire.

Deep cryogenic processing makes the welds and the metal of the dewar last longer in fatigue, and nothing gets more cryo processing than a cryo processing dewar. We have machines in the field that are cycled three times a week with heavy loads, and after many years, they have never developed a leak.

If you have any other questions, please feel free to contact us at the facility nearest you.