| 摘要 |
480,235. Cores for dynamo-electric machines. BRITISH THOMSON-HOUSTON CO., Ltd. Aug. 23, 1937, No. 23072. Convention date, Aug. 24, 1936. Drawings to Specification. [Classes 35 and 38 (ii)] [Also in Group XXII] Sheets for transformer cores, dynamos, &c. are made from steel containing more than 5 per cent and not more than 7 per cent silicon, by casting an ingot, transferring it, while several hundred degrees above room temperature, e.g. 600‹ C., to a furnace and heating (or soaking it for about 4-6 hours) to 1200 to 1300‹ C. and rolling first into bars with reheating for 4-6 hours at 1000 to 1100‹ C. and then rolling into sheets which are doubled and interleaved with softer sheets, e.g. of mild steel containing 3 per cent selenium and heated to not less than 325‹ C., and pack rolled to within a predetermined percentage, 12 per cent, of the final thickness and then finishing by rolling at a lower temperature, e.g. about 850-900‹ C. or, to within 8 per cent of the final thickness and finish rolling at 700 to 760‹ C. The ingot may be transferred to the furnace as soon as it has become solid. The pack of sheets are sheared and separated immediately after the final pass preferably at 200‹ C. or before it drops to 95‹C. A sheet so made and containing from 6 to 6À5 per cent silicon is said to result in minimum noise when used for transformer cores. Specification 380,387, [Group XXII], is referred to. |
