Metal treatment – Process of modifying or maintaining internal physical... – Magnetic materials
Patent
1975-09-02
1976-07-27
Satterfield, Walter R.
Metal treatment
Process of modifying or maintaining internal physical...
Magnetic materials
148 131, 148112, 266106, 13 1, H01F 104
Patent
active
039716791
ABSTRACT:
A batch-type method of annealing large coils of silicon steel for magnetic purposes in an annealing furance of the type comprising an outer enclosure surrounding an insulated heating chamber in which the coils are supported, the furnace being capable of subjecting the coils both to a desired atmosphere and a vacuum. The method comprises the steps of locating the coils to be annealed in the furnace heating chamber; drawing and holding a vacuum within the outer enclosure and heating chamber to remove air therefrom; backfilling with a desired non-oxidizing annealing atmosphere; circulating the annealing atmosphere through the outer enclosure and heating chamber; heating the coils to a temperature of about 2200.degree.F. (1204.degree.C.) and soaking the coils at temperature with continued annealing atmosphere circulation; subjecting the coils to an initial, slow, unassisted cooling step down to about 1700.degree.F. (927.degree.C.); subjecting the coils to an intermediate cooling step down to about 1225.degree.F. (663.degree.C) with the furnace fans on and the furnace bungs closed; subjecting the coils to a final fast cooling step down to about 250.degree.F. (121.degree.C.) with the furnace fans on and the furnace bungs open; drawing and holding a vacuum within the outer enclosure and heating chamber to remove the annealing atmosphere therefrom; backfilling with nitrogen and removing the coils from the furnace. When the silicon steel for magnetic purposes is to have a cube-on-edge orientation and contains Aln as the grain growth inhibitor, the coils may be held at 1200.degree.F. (649.degree.C.) for about 6 hours prior to heating them to 2200.degree.F. (1204.degree.C.) and the soaking step.
REFERENCES:
patent: 3588305 (1971-06-01), Seelandt
Burger John H.
Dunkle Robert P.
McClelland John R.
Armco Steel Corporation
Satterfield Walter R.
LandOfFree
Method of annealing oriented silicon steel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of annealing oriented silicon steel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of annealing oriented silicon steel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1623380