Method for manufacturing bimetal
AssigneeTokyo Shibaura Electric Co., Ltd.
InventorsTatsuyoshi Aisaka, Mitsuo Kawai, Fumio Mori, Shinzo Sugai
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Abstract
A bimetal is disclosed having a high, rapid deflection over a specified temperature range, including a high expansion metal alloy component having a high thermal expansion coefficient that changes rapidy at 50.times.10.sup.-6 /.degree.C. or greater at a temperature of between about 100.degree. C. and 250.degree. C. and containing from 15-30% by weight of manganeses, the balance of iron. The second component has a substantially constant thermal expansion coefficient regardless of the temperature change, and is preferably a stainless steel. These bimetals are used in circuit breakers, thermal protectors and the like.
Claims19
A method of manufacturing a bimetal exhibiting a hysteresis and a rapid deflection over a predetermined temperature range, comprising the steps of:
- (a) providing a first metal component of a high expansion metal alloy whose thermal expansion coefficient rapidly changes from 21.5.times.10.sup.-6 /.degree.C. or less to 50.times.10.sup.-6 /.degree.C. or more at a temperature of between 100.degree. C. and 250.degree. C.,
- said high expansion metal alloy being selected from a first alloy consisting of 15 to 30% by weight of manganese and substantially iron as the remainder or a second alloy consisting essentially of 15 to 30% by weight of manganese, and a member selected from the group consisting of 2 to 15% by weight of chromium, 2 to 15% by weight of cobalt and 2 to 20% by weight of a mixture of chromium and cobalt and the balancce of iron;
- (b) providing a second metal component of a low expansion metal alloy having a thermal expansion coefficient substantially constant regardless of temperature changes;
- (c) annealing the first metal component repeatedly to substantially eliminate work strains contained therein;
- and
- (d) bonding together said first and second metal components.
Dependencies are inferred from the claim text.