一、前 言 D6AC超高强度钢系美国宇航专用钢种。它是60年代初由原来模具钢D6A改进冶炼工艺发展起来的。D6AC钢曾经用于制造F-111型飞机起落架和结构件,阿波罗神登月般的高压储气瓶。近十余年来,在固体火箭发动机壳体方面应用尤为广泛,在制造直径300mm到4m的中大型固体火箭发动机壳体方面有逐步取代其它钢种而成为这 First, the preface D6AC ultra-high strength steel US Aerospace special steel. It is the early 60s by the original mold steel D6A improved smelting process developed. D6AC steel used to make F-111 aircraft landing gear and structural parts, Apollo God-moon high-pressure gas cylinders. In recent ten years, the solid rocket motor shell is particularly widely used in the manufacture of 300mm to 4m diameter medium and large solid rocket motor shell has been gradually replaced by other types of steel as the