Treatments and Services
Heat Treating is the controlled heating and cooling of metals to alter their physical and sometimes chemical properties without changing the shape. Heat treatment is sometimes done inadvertently due to manufacturing processes that either heat or cool the metal such as welding or forming.
Heat Treatment is often associated with increasing the strength of material, but it can also be used to alter certain manufacturability objectives such as improving machining, improving formability and restoring ductility after a cold working operation. Thus it is a very enabling manufacturing process that can not only help other manufacturing processes, but can also improve product performance by increasing strength or other desirable characteristics.
Heat treatment is a method used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. The most common application is metallurgical and involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of a material. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, and quenching.
Annealing is a process typically used to soften metal to ease in machining or forming. We offer a wide selection of annealing processes and equipment.
Whether you are just trying to anneal for machinability or you need a full atmospheric anneal we have the equipment and the know how to do the job for you.
We can anneal in an open air furnace parts as large as 8,000 Lbs each and our largest furnace for this is 72” wide x 60” high x 228” long and can handle 25,000 Lbs.
If it is a full anneal in a vacuum atmosphere you require we can process parts weighing as much as 2,500 Lbs each and our largest vacuum furnace is 46” outside diameter x 57” high with a 2,500 Lbs maximum weight capacity.
Heat treating done under a controlled, gaseous environment, usually devoid of oxygen. By controlling the gases surrounding the part at high temperatures, the part surface can be protected or enhanced. See, Neutral Hardening and Carburizing.
Atmosphere Annealing
Atmosphere Carbonitriding
Atmosphere Carbon Restoration
Atmosphere Carburizing
Atmosphere Normalizing
Quench and Temper
A carburization process that is designed to bring the surface of a casting or forging back to its original carbon content and to restore the hardenability of the surface.
Steel parts are heated to transformation temperature in a carbon and nitrogen-rich atmosphere to form a hard surface of iron carbides and iron nitrides (after quenching) for resisting sliding wear.
Carburizing is a surface hardening treatment used on low carbon and alloy steels to increase the surface hardness of the steel without hardening deep into the core of the steel. The end result is a good wear resistant surface and a strong but ductile core.
This process is commonly used on gears, bearing races or anything requiring a hard wear resistant surface with a strong and ductile core. It is done in a high carbon gaseous atmosphere and the depth of the case depth is in direct correlation with the carburizing temperature and the length of the carburize cycle.
We have four integral quench atmosphere furnaces capable of carburizing parts as large as 2,000 Lbs. Our largest atmosphere furnaces are 30” wide x 30” high x 48” long and all have digital carbon and temperature control.
Carburized steel parts are heated to transformation temperature and quenched in oil (or water) to produce a part with a very hard shell or “case”, but with a ductile core.
Parts are cooled under liquid or gaseous nitrogen to -100F to -300F to remove retained austenite in the steel, or to relieve stresses and make a more homogenous, stable structure.
Heat treating (usually tempering) done in jigs, under pressure to remove distortion or warpage in parts. Also known as flattening.
The controlled application and removal of heat (austenitizing, quenching, tempering, freezing) of a metal part to change its physical properties, to enhance part performance or allow further processing.
Quantifying the relative resistance of metal parts to penetration by a probe of a known size with a given force. Measured in Rockwell, Brinell, Knoop or Vickers scales. Related to tensile strength.
Heat Treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of a material. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering ,normalizing and quenching. It is noteworthy that while the term heat treatment applies only to processes where the heating and cooling are done for the specific purpose of altering properties intentionally, heating and cooling often occur incidentally during other manufacturing processes such as hot forming or welding.
See, Hardening. See also, Annealing.
Determining the microstructure of steel or other metallic parts to predict or to assure their physical properties, e.g., tensile strength, ductility, hardness. Done on a polished sample under a microscope.
We have 58 years of combined heat treat metallurgical experience and can help you with any of your heat treating needs. We are a simple e-mail or phone call away.
You can reach either Mark Tate or David Sullinger at 281-590-9600 or at
Contact us anytime you have a question regarding bidding a job, improving an existing product or whatever your heat treat need may be and we will be glad to assist you.
Heat treating done in an oxygen-free environment that is chemically neutral to the surface of the steel. Endothermic atmosphere or nitrogen blankets are used.
Nitriding is a surface hardening process in which nitrogen present in the atmosphere in the nascent form of N1 diffuses into the surface of the steel and forms nitrides with certain critical elements such as chromium, molybdenum, vanadium, aluminum, tungsten and iron. It can be done in a gas atmosphere, vacuum atmosphere (Ion) or salt bath.
We use the gas nitride process here. We have a state of the art gas nitride furnace with automated controls that is 64” outside diameter x 96” high and can handle up to 15,000 Lbs.
We also have a smaller unit that is 30” outside diameter x 42” deep.
Whether you’re looking for a light case of .002”/.006” or a really deep case of .035”/.040” depending upon the material grade we can build a process to meet your needs.
A heat treat process to bring the microstructure into a condition that facilitates subsequent processes by making the part more homogenous in structure. Usually done on castings or forgings.
Up to 25,000 lbs
4’ x 6’ x 19’
Up to 1900 Deg. F.
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Up to 20,000 lbs
4’ x 4’ x 16’
Up to 1900 Deg. F
A gaseous carburizing process where the gas mixtures, time and temperatures are all controlled continuously throughout the process through digital controls and oxygen probes.
Quenching can be used in heat treating for a number of reasons, but the main reason here is in transforming austenite into martensite. It is the hardening portion of the “harden and temper” process. We can quench in air, nitrogen, oil or water.
Our air hardening limitations are the size of our largest furnace which is 72” wide x 60” high x 228” long and a 25,000 Lb load limit.
Our nitrogen quench limitations are the size of our largest vacuum furnace which is 46” outside diameter x 57” high and a 2,500 Lb load limit.
Our oil quench limitations are 30” wide x 30” high x 48” long and a 2,000 Lb load limit.
Our water quench limitations are 48” high x 60” wide x 192” long and a 7,000 Lb load limit per quench.
Heat treating processes that harden only one area of a part. Also may mean a physical barrier (copper plate or stop-off) is applied to prevent carburization and hardening of an area of the part.
A heat treating process that prepares the material for subsequent low temperature precipitation hardening by artificial aging. Allows “soft” parts to be finished to size before the aging process.
A “softening” of steel by heating and then cooling very slowly to provide a metallurgical structure that looks like “spheres” or “balls.” Allows the metal to be stamped or formed more easily.
See, Hardening.
A post-heat treat process to bring shafts, blades, or other parts into tolerance for straightness.
A heat treating process (usually below 1250F) to remove welding, cold working or other internal strains to avoid part movement during later heat treatment or machining.
Following heat treating cycles, many industries are now requiring Cold and Cryogenic (Deep Freezing) treatments be done in order to increase hardness and wear resistance and to further reduce metal fatigue.
Cryogenic treatments are usually done immediately following quenching and before any tempering is done. It does increase the hardness and wear resistance and reduces metal fatigue, but it may also increase the chances of cracking during the process. This is because cryogenic treatments are really just an extension of the quenching process.
Cryogenics is often used for gears, bearings, tools and other items that require a higher wear resistance and durability. However, it is usually only effective in metals in which more than 10% austenite is retained after quenching, such as high-carbon or high-alloy steels.
WE CAN FREEZE AT TEMPERATURES AS COLD AS -150 FARENHEIT
- LOADS UP TO 3000 Lbs.
- 30” W X 36” H X 50” L
Untempered martensitic steel, while very hard, is too brittle to be useful for most applications. A method for alleviating this problem is called tempering.
Tempering consists of heating steel below the lower critical temperature to impart some toughness.
Age Hardening • Anneal for Machining • Full Anneal • Post Weld Heat Treating (Code Stress Relieve)
Temper Modify • Stress Relieve • Temper Anneal
Tempering is used to draw the hardness out of the as quenched piece of steel. How much as quenched hardness that is drawn out of the steel will depend upon the tempering temperature used and the length of time the steel is held at the tempering temperature.
Sometimes tempering is used to modify an existing heat treat condition in the steel. Typically when the material has already been stocked in a higher than required strength level.
We can temper in a vacuum atmosphere if needed on finished parts and our largest vacuum furnace is 46” outside diameter x 57” high and can handle a 2,500 Lb load.
Our air tempering capabilities are much larger, with our largest available tempering furnace measuring 72” wide x 60” high x 228” long and can handle a 25,000 Lb load.
Metallurgical: See, Metal Testing.
See, Heat Treating.
Heat treating done on parts inside a vessel that has had most of the ambient air removed before heat-up. Since there is no oxygen present, the parts come out “bright.”
Heat treat tool steels
Heat treat stainless steels
Vacuum Age Hardening
Vacuum Full Anneal
Vacuum Normalizing
Vacuum Solution Anneal
Vacuum Temper
Quenching is a process of cooling a metal at a rapid rate. This is most often done to produce a martensite transformation. In ferrous alloys, this will often produce a harder metal, while non-ferrous alloys will usually become softer than normal.
Up to 7000 lbs • 48” x 60” x 192”
Memberships and Certifications
Houston Heat Treat
13802 ChrismanHouston, Texas 77039
281-590-9600