一、前言 铬镍钼钒钢是应用比较广泛的高强度钢种之一,以往人们对它的力学性能影响因素研究得很多。但在实践中往往出现一些现象,如钢中镍、铬、钼含量变化对性能的影响,有时就很难用固溶强化和沉淀硬化理论予以解释。自透射电镜金属薄膜技术问世后,人们用该技术对淬火钢的亚结构进行了大量研究,发现淬火钢中存在着两种不同类型的亚结构——位错亚结构和孪晶亚结构,也找出了影响亚结构类型的一些因素。但是具体地把钢淬火亚结构差别与回火组织及力学性能联系起来的工作并不 I. Introduction Chromium, nickel, molybdenum and vanadium steel is one of the most widely used high-strength steels. In the past, there were many studies on the influencing factors on its mechanical properties. However, some phenomena often occur in practice, such as the influence of the change of the content of nickel, chromium and molybdenum on the performance of steel, and sometimes it is hard to explain the theory of solution strengthening and precipitation hardening. Since the advent of transmission electron microscopy, many studies have been conducted on the substructures of hardened steels using this technique. Two different types of substructures, dislocated and twinned subtypes, have been found in quenched steels Identify some of the factors that influence the type of substructure. However, the work of specifically relating the difference between sub-structural steel quenching and tempering microstructure and mechanical properties is not