Science

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Tel: 01473 657787

Get the optimum performance from your:
HIGH SPEED STEEL - HIGH PERFORMANCE AUTOS - HIGH END AUDIO
With Deep Cryogenic Treatment

The Science

Cryogenics is the treatment of materials at extremely low temperatures. For ferrous steels, sub-zero treatment at temperatures of approximately –80’C transforms retained austenite left by the heat treatment process to martensite (martensite is 4X harder than austenite). During this transformation additional smaller carbide particles are released and evenly distributed through the material resulting in a reduced residual stresses and a very hard, fine carbide lattice structure. Deep cryogenic treatment at temperatures of –185’C further enhances the materials properties. By slowing down atomic movement, the internal molecular bonding energy is increased which promotes a pure structural balance throughout the mass of the material. The end result being a material with an extremely uniform, refined and dense microstructure with vastly improved properties.

Blade_Samp_01.jpg (11608 bytes) Sample a. is a standard blade made from High Speed tool steel. Sample b. is the same blade only it has been cryo treated by Frozen Solid. Tests on the these samples were carried out by an independent lab. These were the labs finding's:Sample b. has a more complete martensite transformation than sample a. Sample b. has gained a further increase in Rockwell hardness, from 61 HRC to 63 HRC.

These images are copyrighted and the property of Frozen Solid

Non-Ferrous

Non-Ferrous materials such as copper and aluminium benefit from deep cryogenic treatment. At the left are samples from one of our customers cables and interconnects that were recently benchmarked in the audio industry. The samples are all oxygen-free-copper (OFC) from the same batch. The top sample is typical of the material as you would receive from the supplier. The middle sample has been deep cryogenically treated. Note how the dislocations are starting to close up. The bottom sample has been treated using Frozen Solids own proprietary cryogenic process . Note the further improvement in the structure.

The Process
One of the most important steps for cryogenic treatment to be effective is process control. When cooling materials the idea is to keep the exterior and interior (core) of the material at the same temperature, thus allowing for the complete transformation of austenite to martensite. Using a microprocessor the components are cooled down at a rate of about a 1/4 of a degree per minute until the material reaches approximately -185C to -190C.The material is then soaked at deep cryogenic temperatures for period of not less than 24 hours. Once the soak is complete the material is then allowed to warm to ambient temperature at a slow controlled rate. Upon soak completion the material may require a post temper. The tempering operation is carried out within the same processing chamber or one of our other tempering ovens. To achieve deep cryogenic temperature levels nitrogen is used. Nitrogen is a non-flammable; non-polluting element, which makes up 80% of the air we breathe, the process, is therefore environmentally friendly and can help companies reduce their Carbon Footprint. Our treatment method is a dry process, so your components never come into direct contact with Liquid Nitrogen. As stated above; for safety reasons Frozen Solid only employs a long soak process on materials thus ensuring a complete transformation of the material and reduces the chances of an embedded matrix within the componet being treated.

The above treatment parameter represents a typical recipe for treatment of industrial steel. Our treatment of non-ferrous materials (copper, aluminium etc.) differ from the treatment of ferrous materials.

The Equipment

aatank01.jpg (55876 bytes) Today computers control the entire process; from the ramp down to cryogenic temperature levels through to the heat tempering phase. The use of computers in the processing has allowed for better process control as well as more predictable results. Our treatment chamber is of stainless steel construction, and up to the most demanding load requirements. And unlike other chambers on the market, ours is a dual purpose unit that also performs the tempering phase, so there is never any disruption to the components during processing. The liquid nitrogen is supplied from an 1000 liter storage tank supplied by BOC Gas. It is the latest in storage tank designs, and is one of the most efficient on the market, with a boil off rate of approximately 1% a day.

Chamber Specifications
Internal Dimensions: 1.5L X .73W X .7H
Volume: 750 Litres
Capacity: 1250 kgs.

Contact Information

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Stowmarket, Suffolk
England

Telephone: 01473-657787 (within the U.K.)
+44-1473-657787 (outside the U.K.)
Fax 01473-657787

Serving the United Kingdom, mainland Europe & beyond