ALUMINUM ALLOY SHEET FOR CROSS FIN AND PRODUCTION THEREOF

摘要

A CONTINUOUS-CAST AND COLD-ROLLED ALUMINUM ALLOY SHEET FOR A CROSS FIN, CHARACTERIZED BY A CHEMICAL COMPOSITION CONSISTING OF NOT LESS THAN 0.05 WT % AND LESS THAN 0.30 WT % FE, MORE THAN 0.03 WT % AND LESS THAN 0.10 WT % MN, AN AMOUNT OF A GRAIN REFMING AGENT, AND THE BALANCC OF AL AND UNAVOIDABLE IMPURITIES INCLUDING LESS THAN 0.15 WT % SI; A MICROSTRUCTURE SUBSTANTIALLY COMPOSED OF SUBGRAINS; AND AN ELECTRICAL CONDUCTIVITY OF 55 % IACS OR MORE. THE ALUMINUM ALLOY SHEET IS ADVANTAGEOUSLY PRODUCED BY A PROCESS INCLUDING THE STEPS OF CONTINUOUS-CASTING AN ALUMINUM ALLOY MELT HAVING THE ABOVE-MENTIONED CHEMICAL COMPOSITION TO FORM A CAST SHEET HAVING A SHEET THICKNESS OF NOT MORE THAN 30 MM; COLD-ROLLING THE CAST SHEET AT A REDUCTION OF 90 % OR MORE, FOLLOWED BY A TEMPER ANNEALING AT A TEMPERATURE OF &OM 250 TO 300° C FOR A HOLDING TIME OF 2 HOURS OR MORE. THE PRESENT INVENTIVE ALUMINUM ALLOY SHEET HAS A HIGH FORMABILITY SUCH THAT A CROSS FM HAVING A LARGE FM PITCH APPLICABLE TO ANY TYPE OF HEAT MEDIA PIPE HAVING VARIOUS SIZES CAN BE SUCCESSFULLY FORMED BY A SIMPLIFIED PRODUCTION PROCESS WHICH IS EASY TO MANAGE AND ALSO REDUCES THE PRODUCTION COST AND BY USING LESS VISCOUS VOLATILE LUBRICANTS CAUSING NO SUBSTANTIAL ENVIRONMENTAL POLLUTION.