Heat treatment
Annealing
Annealing makes the material softer and more machinable. The part is heated and cooled slowly inside the furnace.
What we do
- Full and subcritical annealing
- Furnaces with temperature and time control and recording
- Forgings, bars, blocks and machined parts
- Report with the cycle applied and, on request, mechanical tests after treatment
Materials
Capacity, maximum dimensions and lead time on request: send the drawing. See alloys in stock.
How annealing works
The part is heated to the annealing temperature of the alloy, held and cooled slowly, usually inside the furnace. The slow cooling produces the softest possible structure for that material. In full annealing the steel passes through the critical range; in subcritical annealing it stays below it, which is enough to soften and relieve stresses without changing the whole structure.
When to use it
Annealing prepares the material for difficult operations: heavy machining of hard alloy steels, cold forming and reworking of parts that have work-hardened. It is also used on martensitic steels after forging, to avoid cracks while the part waits for quenching. In nickel alloys and stainless, the term "annealing" usually means solution annealing, with fast cooling.
Result and checking
The hardness after annealing is measured and compared with the maximum of the standard (for example, the maximum hardness in the annealed condition given for 4140 steel). The actual cycle is recorded and accompanies the part.
What to send with a quote request
To get a quote, send the alloy and standard of the material, the drawing or the dimensions of the part, the quantity, the required cycle (or the hardness and properties to be reached) and whether verification tests are needed. Parts that will still be machined are treated with allowance, so that the oxidized layer is removed in finish machining.
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Frequently asked questions
Are annealing and solution annealing the same thing?
In carbon and alloy steels, no: annealing softens with slow cooling. In austenitic stainless and nickel alloys, the market calls "annealing" what is technically solution annealing, with fast cooling.
Does annealing reduce the strength of the material?
Yes, on purpose: it makes the material softer. If the part needs high strength in service, after machining it goes to quenching and tempering.
Does Dustre perform this service on customer-supplied material?
Yes, as long as the alloy and the specification are defined. We can also supply the material from our stock, with EN 10204 3.1 certificate.
