What is overshoot or overheating?

What does overshoot mean when a temperature uniformity survey (TUS) is considered unsuccessful?

First of all, I would like to give you the definition of this word used in AMS 2750H .

2.4.74 TEMPERATURE OVERSHOOT

When any temperature sensor exceeds the upper temperature tolerance as defined by the applicable thermal processing equipment class as stated in Table 8.

The situation that occurs when any temperature sensor exceeds the upper temperature tolerance defined by the standard used in that test is called overshoot or overheating.

For example,

According to CQI-9 Table C, temperature uniformity for an aluminum aging furnace is ±5°C. If this furnace rises 5°C above the setting temperature during TUS or production, this furnace is overshooted .

The requested uniformity for a Class 3 furnace to AMS 2750H is ±8°C. If an furnace set at 900°C reaches 908.1°C at the time of production or during TUS, this is called overheating.

I am adding a visual for a clearer understanding. In the example below , some of the TUS sensors in an furnace set at 540 °C exceed the upper tolerance limit of 545 °C, well above 560 °C. This is a reason for failed TUS.

How can BDİ Metal help you?

Field test equipment and experienced teams can calibrate your furnaces in accordance with AMS 2750H, ASTM A991 and CQI-9 requirements. We can provide you with technical support to prevent possible overheating.