添加铌（Nb）和钒（V）对普通碳素钢性能的影响已众所周知多年。最近，通过加工技术的改进，非常有效地使用了相对少量的Nb或V（高达0.2 wt-%），以显著提高屈服强度和改善缺口韧性。这些改进是通过优化Nb和V碳氮化物沉淀硬化、细化铁素体晶粒和降低C含量实现的。后一项也显著提高了可焊性。 世界上几乎所有的工业化国家都利用了以最低的额外合金化成本生产高强度钢的经济优势。 这对于结构应用尤其如此，因为在结构应用中，重量节省非常重要。美国无疑是这一领域的领导者之一，只要看看美国金属学会（ASM）最近对高强度低合金（HSLA）结构钢的调查，就可以看到各种各样的含铌和含钒钢。 许多国家也在压力容器应用中有效地使用了这些钢。尽管美国在高压管线管道开发方面非常活跃，但很少有人将铌和钒钢用于压力容器和其他容器。 主要原因是美国机械工程师协会（ASME）锅炉和压力容器规范规定的许用应力计算通常由抗拉强度决定。虽然添加Nb和V可显著提高屈服强度，但对拉伸强度的影响相对较小。因此，通过提高屈服强度，在压力容器设计中无法获得直接优势。 本报告旨在总结压力容器用含铌和含钒C-Mn钢的现状，并确定需要进一步研究的领域。 具体而言，本报告将涵盖屈服强度上限约为75 ksi（53 kg/mm2）的低合金钢。本文简要概述了世界各国压力容器规范，以便为压力容器设计中的重要材料特性提供依据。

The effects of niobium (Nb) and vanadium (V) additions on the properties of plain carbon (C) steel have been well known for some years now. Recently, through refinements in processing technology, very effective use has been made of relatively small amounts of Nb or V (up to 0.2 wt-%) to significantly increase yield strength and improve notch toughness. These improvements have resulted through optimization of Nb and V carbonitride precipitation hardening, ferrite grain size refinement, and a reduction in C content. The latter item also significantly improves weldability. Nearly all of the industrialized countries of the world have taken advantage of the economy of producing higher strength steels with a minimum of extra alloying cost. This is especially true for structural applications where weight savings is so important. The United States is certainly one of the leaders in this area and one only has to look at a recent American Society for Metals (ASM) survey of high-strength low-alloy (HSLA) structural steels to see the wide variety of Nb- and V-containing steels available. Many countries have also made effective use of these steels for pressure vessel applications. Although the United States is very active in high-pressure line-pipe development, very little activity has been directed toward using Nb and V steels for pressure vessels and other containers. The principal reason is that allowable-stress calculation as specified by the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code is usually governed by the tensile strength. While yield strength is increased significantly by Nb and V additions, there is a relatively small effect on tensile strength. Consequently, no direct advantage can be gained in pressure vessel design by an increase in yield strength. It is the purpose of this report to summarize the state of the art of Nb- and V-containing C-Mn steels for pressure vessel applications and to identify areas needing further research. Specifically, this report will cover low-alloy steels with an upper yield-strength range of about 75 ksi (53 kg/mm2). A brief summary of the pressure vessel codes around the world is presented in order to provide a basis for important material properties in the design of pressure vessels.