Overheating


Also found in: Dictionary, Thesaurus, Financial, Wikipedia.

Overheating

 

(metallurgy), a defect that results from heating metals and alloys to high temperatures; the defect is most pronounced when the heating time is extremely long. Steel overheats between 1000° and 1300°C.

After cooling, an overheated metal’s crystal structure is coarse-grained, with distinct, linear boundaries between the components; furthermore, the metal’s resilience is reduced. Overheating can occur during furnace treatments and around seams that have been electrically welded.

In many cases, overheating may be eliminated by a second heating, usually to a temperature 20°-30°C above the recrystallization temperature. This procedure serves to reduce grain size. With alloys of nonferrous metals and with austenitic and ferritic steels, all of which are usually not subjected to recrystallization, overheating cannot be eliminated by repeated thermal treatment; thus, the overheated samples must be rejected as scrap.

The tendency of steels toward overheating depends on their chemical composition and is significantly reduced by adding small amounts of vanadium, titanium, aluminum, or boron.

V. M. TYMCHAK

References in periodicals archive ?
'The uncertainties around Brexit and managing the risk of overheating increase both the challenge and importance of charting the appropriate fiscal policy path.
This overheating problem is already affecting a lot of owners, but it's still unclear wether or not this is affecting majority of Pixel 3 users.
Should overheating occur, diagnosing and replacing a damaged SSR can take time while the assembly line or manufacturing system is down and out of service, cutting into operations and running up expenses.
Overheating happens when the present demands on the economy significantly exceeds its present capacity to provide.'
A common cause of engine overheating is low coolant (also known as antifreeze).
The overheating represents a fire hazard and while no fires
Troubleshooting found switch overheated, burned and power wire showed evidence of overheating. Cessna service bulletin SB09-6 requires inspection and replacement of landing light switches but does not identify the R172E (T-41C), which has a different p/n.
Engine overheating is a common phenomenon, but if you continue driving when your engine is overheated, chances are that you will blow the cylinder head.
21 ( ANI ): Japan's National Consumer Affairs Center has reportedly issued a warning about smartphones overheating after an yearly surge in smartphone-caused burn accidents was witnessed.
That overheating and one a few days earlier on a 787 parked at Boston's Logan airport prompted aviation regulators in the US, Japan and elsewhere to ground the global fleet of Dreamliners for more than three months.
The latest incident involving Boeing's newest jetliner comes a year after overheating batteries on 787s prompted aviation regulators worldwide to ground the aircraft for more than three months.
Risk of overheating and catching fire Recalled March 2012