ALUMINUM ALLOY SHEET FOR PACKAGING HAVING EXCELLENT CORROSION RESISTANCE AND ITS PRODUCTION

摘要

PURPOSE:To develop an Al alloy sheet for packaging having excellent corrosion resistance without generating galvanic corrosion even with a can material made of a mild steel sheet by using a specifically composed Al alloy sheet as a cap material of a can for salt-contg. drinks. CONSTITUTION:An Al alloy sheet contg. 0.50-2.0% Mg, 0.10-0.70% Si, 0.30- 1.5% Mn and 0.10-1.0% Cu is used as a metallic can for packaging food contg. salt such as health drinks, tomato juice, etc. and particularly a cap material thereof. An ingot of the Al alloy having the above-mentioned alloy is made into a sheet material having the thickness of =1.5 times the final thickness by hot rolling and cold rolling. The sheet material is quickly cooled after heating and holding to and at =500 deg.C and is worked by final cold rolling to a sheet material having a prescribed thickness. The Al alloy sheet which -700--630mV in the natural electrode potential in 0.1% salt water kept at 25 deg.Cwith an AgCl electrode as a reference electtode, decreases corrosion by the contents of salt- contg. food and is suitable for a can material and particularly the cap material thereof is obtd.