21-4N气伐钢是美国1952年研制成功的,六十年代已经在世界各国广泛应用,用作中高负载汽油机排气伐。我国在七十年代纳入了标准 YB/ Z8-75,近几年来,用量大幅度增加, 1984年近千吨,予计今后几年需求量将会急剧上升。但是,钢厂供货21-4 N钢的晶粒度和成品气伐的晶粒度如何选择,晶粒度对钢的性能影响大小,还是一个未解决的问题。本文根据一些试验研究,针对上述问题作些探讨。 21-4N gas-cutting steel was successfully developed by the United States in 1952. In the 1960s, it has been widely used in various countries in the world for the purpose of exhaust gas cutting of medium- and high-load gasoline engines. China in the seventies into the standard YB / Z8-75, in recent years, a substantial increase in the amount of nearly 1,000 tons in 1984, the expected future demand will rise sharply in the next few years. However, the steel supplier 21-4N steel grain size and finished product gas cutting grain size, grain size of the steel performance of the size, or an unsolved problem. This article based on some experimental research, to explore some of the above issues.