一、前言上海船厂生产的45钢钢锭常在铸造或锻造加工后发现纵裂缺陷而报废,其中以10时和16时锭为最严重。冶炼设备为1.5吨电弧炉,炉料中加或不加废钢屑,采用加Al终脱氧工艺。10时及16时锭采用中注管浇注。10时锭一次浇出8根,16时锭一次浇出3根。浇注后间隔一段时问,然 I. Foreword 45 steel ingot produced by Shanghai Shipyard is often scrapped after founding or forging process, of which ingot is the worst at 10 o’clock and 16 o’clock. Smelting equipment for the 1.5-ton electric arc furnace, charge with or without scrap steel scrap, the use of Al final deoxidation process. At 10 o’clock and 16 o’clock ingot pouring. 10 when the ingot pouring 8, ingot 16 pouring 3. After pouring interval asked, however