Types of Heat Treatment
July 15th, 2022
Heat treating ovens, or furnaces, are used to harden, soften, or treat metals by way of extreme heating and cooling techniques. Heat treating is used throughout all industries. From consumer goods like cars and computers, to medical devices like implants and surgical tools, to industrial equipment like hydraulic pumps and heavy duty machinery—heat treating remains a critical step in the production of nearly any metal product used today.
In this blog, we’ll distinguish between the different types of heat treating processes and go over important considerations to keep in mind when selecting a heat treat oven for your application.
What is Heat Treating Used For?
The type of heat treatment best suited to your application will depend on the needs of the material. Ferrous metals like iron and steel account for the majority of heat treated materials, however; alloys like aluminum, copper, magnesium, nickel, and titanium can also be heat treated. Depending on the specific process used, heat treating can achieve a variety of outcomes, including:
- Softening material to improve workability
- Hardening material to improve strength
- Toughening materials to reduce brittleness
- Creating a hard surface on soft material to increase abrasion resistance
- Creating a corrosion-resistant surface on otherwise corrosion-susceptible materials
- Relieving stress from materials that have undergone prior cutting or forming
Types of Heat Treatment Furnaces & Ovens
An annealing furnace functions by heating a material above its recrystallization temperature, but below its melting temperature, causing new grains to form without any residual stress. The material is then cooled at a controlled rate in the furnace to increase its ductility and reduce brittleness.
Austenitizing furnaces, otherwise known as hardening furnaces, are designed to heat alloys above their critical temperatures until the desired transformations take place. The materials are then cooled rapidly, resulting in a tough outer casing and a strong inner core.
Similar to annealing, normalizing involves heating a material above its recrystallization temperature, but below its melting temperature. Unlike annealing, the material is then placed in a room temperature environment to cool. Normalizing results in an end product with less ductility but more hardness than if it had been annealed.
In quenching, a component is heated to a suitable temperature and then immersed into water, oil, or some other liquid to cool and harden. The material can be quenched until it returns to room temperature or for an extended period of time for coolness that’s more evenly distributed.
Stress Relieving Furnaces
The stress relieving process is ideal for material that has undergone stress from a metal forming method like cutting, machining, or forging. The component is heated slightly below its transformation temperature and then is slowly cooled to reduce residual stress. Unlike annealing, stress relieving does not change the material’s properties.
The Importance of Maintaining Temperature Uniformity in Heat Treat Ovens
Maintaining temperature uniformity in industrial heat treat ovens ensures consistent quality across all products. When the temperature is subject to frequent fluctuations or uneven hot/cold areas, it’s very possible the material will have to be reworked post treatment, wasting time and money in the long run. Not to mention, energy costs are much higher in ovens that are constantly working to regulate temperatures.
How Do Kleenair Industrial Ovens Effectively Manage Temperature Consistency?
While simple insulating tactics may work for low-temperature ovens, industrial heat treating ovens can run at temperatures as high as 1,000°F and usually require extra measures to adequately prevent heat loss. Kleenair creates heat treating ovens designed to maintain optimal temperature consistency every time. When you buy a heat treatment oven from Kleenair, you also receive:
- Intuitive controls/HMIs to easily program time and temperature requirements
- High quality door seals, door actuators, and door hinges to prevent heat from escaping
- Single or multiple load(s)/unload(s) access doors
- Advanced combustion and insulation systems that conform to AMS 2750 temperature uniformity standards
Leading Manufacturer of Custom Heat Treating Ovens & Furnaces
Kleenair Product Co. is a leading manufacturer of high quality custom heating furnaces and heat treating ovens. We can design, engineer, manufacture, and install your furnace according to your unique process requirements. We pride ourselves on the delivering the most reliable, highest quality furnaces in the industry—with temperature uniformity and usability that is unmatched.
View our extensive selection of industrial heat treating ovens & furnaces and the popular custom drop bottom batch ovens. Request a quote today or contact us to begin discussing your heat treatment needs.