一、前言现代重工业中,随着船舶、冶炼设备和发电设备等锻钢件的大型化,使用的钢锭也在向着400t、500t的超大型化方向发展。这样大型的钢锭,缩孔缺陷和称为中心疏松的、在钢锭轴心部位产生的空隙性缺陷的范围就会扩大,缺陷的尺寸也会增大。缩孔及中心疏松这种内部脆弱的 I. INTRODUCTION In modern heavy industry, with the enlargement of forged steel parts such as ships, smelting equipment and power generation equipment, the ingots used are also moving towards the oversized scale of 400t and 500t. Such a large steel ingot, shrinkage cavity defects and the so-called loose center of the center of the ingot produced in the area of ​​the gap will be expanded, the defect size will increase. Shrinkage and loose center of this fragile