【论文】低合金高强度钢的研究与分析.docVIP

摘要 钢铁是国民经济建设的物质基础，工农业生产和人民生活都离不开钢铁材料。高强度钢就是根据这种需求为适应航空航天技术需要而发展起来的一种比强度高的结构材料，其显著特点是具有超乎一般的高强度。超高强度钢室温抗拉强度a超过1400MPa，屈服强度大于1300 MPa的称为超高强度钢。高强度钢除要求1400 MPa以上的抗拉强度外，还要有一定塑性和韧性，尽可能小的缺口敏感性，高的疲劳强度，一定的抗蚀性、良好的工艺性，符合资源情况及价廉等。AlSI4340 钢是一种典型的中碳低合金高强度钢，已大量应用于火箭发动机外壳、飞机着陆部件、防弹钢板等领域，其使用范围还在不断的扩大，具有广阔的发展前景。 关键字 低合金高强度钢；AlSI4340钢；抗拉强度；屈服强度 Abstract Steel is the material basis of the national economic construction, industrial and agricultural production and peoples lives are inseparable from the iron and steel materials. High-strength steel that is based on this demand developed to meet the needs of the aviation and aerospace technology and a high specific strength structural materials, its significant characteristics are beyond the usual high intensity.Room temperature tensile strength of a ultra-high-strength steel than 1400MPa, yield strength greater than 1300 MPa called ultra-high-strength steel.High-strength steel in addition to a tensile strength of 1400 MPa or more is required, but also have a certain plasticity and toughness, as small as possible notch sensitivity, high fatigue strength, a certain corrosion resistance, good process, consistent with the resource situation andinexpensive. AlSI4340 Steel is a typical medium-carbon low-alloy high strength steel, have been widely used in the field of rocket motor casing, aircraft landing parts, bullet-proof steel, its use continues to expand, and has broad prospects for development. Keywords low-alloy high-strength steel AlSI4340 steel Tensile strength The yield strength 1 绪论 1.1　研究意义 低合金超高强度钢是在调质结构钢的基础上发展起来的，在钢中加入少量的多种合金元素，使钢固溶强化并提高钢的淬透性与马氏体回火稳定性。主要合金元素是锰、铬、硅、镍、钼、钒等，其合金元素总含量一般不超过5％。这类钢与一般合金结构钢相比，除钼含量稍高外，其它元素基本上无多大差别，大致可分为铬钼钢、铬镍钼钢、铬锰硅钢、铬锰硅镍钢、硅锰铝钒钢等几个钢系。含碳量一般为O．27％～O．50％。最终热处理一般是淬火加低温回火或等温淬火。使用状态下的组织是回火马氏体或下贝氏体，其强度主要取决于钢中含碳量或者说马氏体固溶的碳浓度。 研究表明，低合金超高强度锯的抗拉强度与含碳量里的直线关系：plot=(294XC％+82)×9．8MPa式中，C％表示钢中碳含量，适用范围为O．30～0．50％。按公式计算，当碳含量为0．30％时，钢的强度在1700MPa左右：碳含量为O．40％时，强度为2000MPa左右，若碳含量高到O．50％时，钢的强度接近2300MPa。含碳量对钢性能的影响是非常显著的。随着含碳