| 摘要 |
1466364 Production of sintered metal strip BRITISH STEEL CORP 3 May 1974 [3 May 1973 31 Jan 1974] 21103 and 04500/74 Heading C7D A continuous process of producing sintered metal strip in which the green strip is supported on a gas cushion as it is transported through the sintering furnace and the tensile stress applied to the strip during its passage through the furnace is substantially zero e.g. < 50 K neutons/sq. m. for ferritic stainless steel and < 70 K neutons/sq. m. for austenitic stainless steel. The gas cushion may be argon and/or nitrogen optionally with hydrogen and a hydrocarbon. The metal powder 1 is rolled at 2 and the green strip S passes via pinch rolls 4, floration table 5 where it is supported by gas from inlet 11, furnace 6 where it is supported by gas from nozzles 15 and pinch rolls 7 to coiler 8. The tensile stress in the green strip is controlled by regulating the speeds of rolls 4 and 7 via controller 10 in accordance with the measured shrinkage or stress in the strip passing through the furnace. The gas from nozzles 15 may be recirculated via a cooler, compressor and purifying chamber. The sintered strip may be hot-rolled by rolls 7 prior to coiling or cold-rolled after coiling and reheated in the sintering furnace or a separate furnace. The N2 or C content of the steel strip may be adjusted by using a gas cushion of argon and nitrogen or argon and methane e.g. with 25% N 2 -55% A - 20% H2 the N2 content of austenitic stainless steel strip is increased by 0À2%. The green strip may also be formed by depositing a slurry of metal powder and binder on a substrate then drying and rolling the deposited film. |
