Forging Temperatures

[Jeff37]

Hi,
I'm wondering if anyone can help with a very basic question. I've often looked up recommended forging temperatures for various metals in supplier datasheets or books and they'll usually say something along the lines of " typically forged in the range of 1010-1095°C" or "Forging Temperature: 980-1120°C" whereas others will say something along the lines of "Forge from 1120°C with no deformation below 925°C". The latter is clear, but where the former is concerned should this be taken to mean that no forging should take place once it's dropped below the lower temperature or does it represent the range of soaking temperatures prior to forging?
Thanks,

 

[Jughandle]

The many degrees of freedom (so to speak) in the processing can take forging into an art. Consider the variables such as the rate of heat loss to the surroundings, geometry of the part, type of material, closed or open dies, strain rate, capital equipment, and economics (where the goal is to move metal without a reheat), not to mention the skill of the labor force. Wish I could give a better answer to your questions besides ‘maybe’.

 

[EdStainless]

In general when I see a tight range of <100C listed I take it as the soak/start hot work temp.
How low you can go is the art of forging.
Depends on the grade, the press, the reductions, and a long list of other issues.


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P.E. Metallurgy, Plymouth Tube

 

[SJones]

It depends upon the degree of control required by the purchaser of the forgings, and the quality management system of the forging manufacturer. Oil and gas standards, such as API Specification 20B, or DNVGL-RP-0034, demand that forgings are produced according to a manufacturing procedure specification wherein the term "hot working temperature range" is used. This is pretty self-explanatory. A forging establishment with an ISO 9001 certificate, or equivalent, should have a quality system procedure to address the forging operation that details their understanding of the application of temperature control.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.