Abstract
A thorough literature search showed that there is no satisfactory test to aid the selection of a lubricant in hot forging of steel. Lubricant effectiveness under difficult forging conditions has therefore beeninvestigated.
An experimental test rig was designed, developed and constructed in
which hot specimens of temperature 900°C to 1300°C were forged. The forging condition was such that as in industry a lubricant would be used.
Stresses were monitored by means of a Wheatstone bridge network using resistance strain gauges in conjunction with an ultra violet recorder (U.V.R.).
The findings were critically compared with previous investigations on friction during hot forging. Relationships between the known conventional values for the co-efficient of friction and the force
required to eject from a conical die were considered.
reduction in the ejection load when using a lubricant was consistently demonstrated.
The results confirmed that the concept of a simple numerical value of a co-efficient of friction, could not be applied to practical not working operations.
Regression analysis techniques were therefore employed to examine the results in order to find relationships between variables.
Changes in the 'slug' temperature, lubricated or dry condition and die draft angle were made and significant differences in forging loads
were obtained.
A method for measuring lubricant effectiveness by direct comparison
of loads for a dry condition and lubricated condition is suggested.
Key Words: Hot Forging - Steel - Lubrication - Friction
| Date of Award | Jan 1980 |
|---|---|
| Original language | English |
| Awarding Institution |
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Keywords
- friction and lubrication
- hot forging steel