What is Annealing?
Annealing is a heat treatment that alters the properties of a metal. This process is applied to many types of metals, such as steel and cast iron, and it is used mostly to increase the ductility and reduce the hardness of a material. Annealing is often performed after material has undergone a hardening or cold working process to prevent it from brittle failure or to make it more formable for subsequent operations.
Benefits of Annealing
- Annealing improves the formability of a material and its machinability. A material that is hard and brittle can be difficult to bend or press without breaking it. Annealing reduces the hardness to reduce the wear of the metal.
- Removes residual stress
- Improves elasticity
- Enhances electrical conductivity
Annealing Process
Annealing changes the physical and sometimes the chemical properties of a material to increase ductility and reduce the hardness. An annealing furnace works by heating a material above the recrystallization temperature and then cooling the material once it has been held at the desired temperature for a suitable length of time.
- Recovery Stage: In the first phase of the annealing process, a furnace or other type of heat source is used to raise the temperature of the material to a point that removes internal stresses, this results in softening the metal through the removal of primarily linear defects called dislocations. This stage occurs at a lower temperature.
- Recrystallization Stage: The temperature of the metal is raised by applying more heat just below its melting point and high enough that the atoms recrystallize but do not melt. This causes new grains to form without any pre-existing tension.
- Grain Growth Stage: New crystal grains are developed as the grain grows, and this growth is controlled by letting the material cool down at a certain rate. After the completion of these three stages, the material becomes more ductile and hardness is reduced. Once the metal is annealed, final processes such as shaping, stamping or forming are applied.
Common Applications for Annealed Metals
Annealing is used across many types of industries, from construction and manufacturing to automobiles and even jewellery.
- Metal wire that has been drawn from one size to a smaller size might need to undergo an annealing process
- Machining operations that create high amounts of heat or material displacement may need an annealing process afterwards
- Welded components: annealing is often used to recreate uniform physical properties
- Semiconductor industry: silicon wafers are annealed
What is the Difference Between Annealing and Tempering?
The main difference between annealing and tempering is that annealing involves heating the steel to a specified temperature and then cooling at a very slow and controlled rate while tempering involves heating the metal to a precise temperature below the critical point.
Equipment Required for Annealing
Annealing requires a heating device, most commonly a furnace capable of reaching temperatures between 700 °C and 900 °C although some can reach 1000 °C or higher. The type of furnace depends on the needs of the metal. For high volume process annealing, gas fired furnaces are often used.
Riley Surface World has a range of furnaces that are suitable for annealing right across the temperature range (650°C +). Alternatively, for smaller parts and components try our Lab/Bench Top Ovens or Bench Top Furnaces.
SNOL 1100°C - 1300°C Muffle Furnace Range
The economical muffle furnace is designed for general workshop and laboratory heat treatments up to 1300°C and up to 39 litres.
- Stock No
- NEW073
- Category
- Tool Room & Bench Top Furnaces
- Model
- SNOL LHM01
- Internal Size (WxDxH mm) [?]
- Various
- Max Temp
- 1100°C, 1300°C
- Condition
- Brand New
- Availability:
- Available subject to build time
- Price [?]
- Please call on +44 (0) 1922 45 8000
SNOL 1100°C - 1300°C Chamber Furnace Range
SNOL's LSF01 is a compact laboratory furnace, suitable for applications in the laboratory or light industry setting, especially when multiple or larger test samples are required.
- Stock No
- NEW074
- Category
- Tool Room & Bench Top Furnaces
- Model
- SNOL LSF01
- Internal Size (WxDxH mm) [?]
- Various
- Max Temp
- 1100°C, 1200°C, 1300°C
- Condition
- Brand New
- Availability:
- Available subject to build time
- Price [?]
- Please call on +44 (0) 1922 45 8000
Hendrick Industrial Equipment Ltd Through Feed Double Bogie Shuttle Heat Treatment Furnace to AMS 2750 rev E
Hendrick Industrial Equipment Ltd Pre-oxidization and Annealing Furnace with 2 rail mounted carts/ bogeys to allow components to be wheeled into and out of chamber. 0-925°C temperature range, switchgear, accessories and spares, rebuilt in 2003.
- Stock No
- OA2255
- Category
- Industrial Furnaces
- Model
- Hendrick Industrial Equipment Ltd Bogie Hearth
- Year of Manufacture
- 2003 (Ref)
- Internal Size (WxDxH mm) [?]
- 1050 x 900 x 500
- Max Temp
- 1050°C rating of 40kW
- Other Info
- 12 Point Survey AMS 2750 rev E
- Condition
- From a working environment, Good Condition
- Refurbished Price [?]
- £ Login or Register for price.
- Sold As Seen Price [?]
- £ Login or Register for price.
Made In Germany Carburising Electric Pit Furnace
A versatile 130kW Carburising furnace utilising Homocarb© fluid to create the atmosphere. Manual or automatic operation of temperature and atmosphere set points with a maximum working temperature of 1000°C
- Stock No
- OA2269
- Category
- Industrial Furnaces
- Model
- Made In Germany Carbo Drop
- Year of Manufacture
- Ref 2018
- Internal Size (WxDxH mm) [?]
- Charge size 900 Ø x 900 high
- Max Temp
- 1000°C with cooling facility
- Other Info
- AMS2750 rev E from 500°C to 950°C
- Condition
- Seen working by RSW, Excellent Condition
- Sold As Seen Price [?]
- £ Login or Register for price.
Watkins Johnson Mesh Belt Furnace
This Watkins Johnson 6 zone furnace consists of the following major components and operational features. Eurotherm Mini 8 programmable controller linked to an external PC. 6 zones with 2 side, 1 top and 1 bottom element in each zone. Variable belt speed control.
- Stock No
- OB2281
- Category
- Industrial Furnaces
- Model
- Watkins Johnson 6 zone Furnace Model 14TF
- Internal Size (WxDxH mm) [?]
- 355 wide x 80 high above belt
- Max Temp
- 900°C
- Other Info
- Variable Speed Conveyor Belt.
- Condition
- From a working environment, Excellent Condition
- Sold As Seen Price [?]
- £ Login or Register for price.
Metritherm 6 Zone Atmosphere Low Temperature Mesh Belt Furnace
This is a 6 zone atmosphere low temperature conveyor furnace . The furnace was used for glass to metal sealing at 620°C with nitrogen.
- Stock No
- OB2283J
- Category
- Industrial Furnaces
- Model
- Metritherm 6 Zone
- Year of Manufacture
- Ref 2019
- Internal Size (WxDxH mm) [?]
- 150mm Wide belt x 70mm Tall aperture
- Max Temp
- 680°C
- Other Info
- Belt width 150mm
- Condition
- From a working environment, Good Condition
Almor Group Top Loading Chamber Furnace
Top loading high temperature tool room/laboratory furnace. 1400°C approx. 2 Litres.
- Stock No
- OB2288
- Category
- Tool Room & Bench Top Furnaces
- Model
- Almor Group FF2 Top Loading Tool room Furnace
- Internal Size (WxDxH mm) [?]
- 120 x 120 x 120
- Max Temp
- 1400°C
- Other Info
- Unrestricted Loading
- Condition
- Excellent Condition, Seen powered at RSW
- Availability
- Available for immediate collection
- Sold As Seen Price [?]
- £ Login or Register for price.
S G Nitriding Furnaces Bell Style, Controlled Atmosphere, Nitriding Furnace
The SG nitriding, bell style furnace has been specified and built primarily as a gas nitriding furnace operating under a monitored gas environment. But with its 1175°C temperature range, it is also suitable for a wide range of other heat treatments including; carburising, carbonitriding, annealing, brazing and nitrocarburizing.
- Stock No
- OC2416
- Category
- Industrial Furnaces
- Model
- S G Nitriding Furnaces Gas Nitriding Bell Furnace
- Year of Manufacture
- Ref 2016
- Internal Size (WxDxH mm) [?]
- Ø550 x 750
- Max Temp
- 1175°C
- Other Info
- New CSM 40mm Seal fitted in 2016
- Condition
- From a working environment, Good Condition
Furntech Electric Heavy Duty Front Loading Industrial Furnace
The electric single zone heat treatment furnace is designed to use an arrangement of heater elements located on either side of the heating chamber, providing the best possible control of heat transfer, temperature uniformity, and fuel efficiency.
- Stock No
- OD2513
- Category
- Industrial Furnaces
- Model
- Furntech Front loading vertical door
- Internal Size (WxDxH mm) [?]
- 1060 x 1470 x 660 highest point
- Max Temp
- 1100°C
- Other Info
- Eurotherm 6100A Data Recorder
- Condition
- Seen working by RSW, Good Condition
- Refurbished Price [?]
- £ Login or Register for price.
- Sold As Seen Price [?]
- £ Login or Register for price.
Wessex Furnaces 670°C AMS 2750 Heavy Duty Air Circulated Box Oven
This steel lined, 670°C, roller hearth, industrial, air circulated oven has a large chamber size of 950mm x 1000mm x 950mm. Featuring a vertical lifting door, Eurotherm 3208 PID controller and Eurotherm 3216 over temperature controller.
- Stock No
- OD2531
- Category
- Industrial Furnaces
- Model
- Wessex Furnaces AMS 2750 Class 5 Vertical Door
- Year of Manufacture
- 1999
- Internal Size (WxDxH mm) [?]
- 950 x 1000 x 950
- Max Temp
- 670°C
- Other Info
- AMS 2750 Class 5 Industrial Box Oven
- Condition
- From a working environment, Excellent Condition
- Refurbished Price [?]
- £ Login or Register for price.
- Sold As Seen Price [?]
- £ Login or Register for price.
Linn High Therm GmbH Microwave High Temperature Chamber Furnace
This high power microwave furnace was designed especially for powder metallurgical processes such as ashing, calcination, melting and sintering. The chamber is gas and vacuum tight with special safety features to protect the operators from emerging microwave radiation. Includes several optional extras.
- Stock No
- OD2552J
- Category
- Industrial Furnaces
- Model
- Linn High Therm GmbH MKH-7,2
- Year of Manufacture
- 2016
- Internal Size (WxDxH mm) [?]
- Useful Volume 27L, Chamber 156L
- Max Temp
- 1800°C // 1700°C Continuous
- Other Info
- 7.2kW of Microwave Power
- Condition
- From a working environment, Excellent Condition, Current Model
- Sold As Seen Price [?]
- £ Login or Register for price.
Pollution Control Products Organic Coating Burn off Furnace
Controlled Pyrolysis burn off furnace.
- Stock No
- OZ2092
- Category
- Industrial Furnaces
- Model
- Pollution Control Products Euro99 SCTR 9 Modified depth
- Year of Manufacture
- 1999
- Internal Size (WxDxH mm) [?]
- 580 x 4000 x 1150
- Max Temp
- Primary 450°C, Secondary 800°C
- Other Info
- Unique 4 Meters Working Depth
- Sold As Seen Price [?]
- £ Login or Register for price.
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