Abstract: In order to develop low alloy ultra-high strength steel with super high strength and good toughness, a 15 mm CrNiMo-CrNi3Mo-CrNiMo triple-layer clad ultra-high strength steel is developed by 30MnCrNiMo steel billet and 33MnCrNi3Mo steel ingot, the process consists vacuum combined welding, high temperature rolling, quenching and low temperature tempering heat treatment. The bonding degree and mechanical properties are tested by flaw detection, tensile, impact, cold bending and hardness tests. Microstructure and the impact fracture of triple-layer clad ultra-high strength steel are analyzed by means of optical microscope and scanning electron microscope. Results show that the triple-layer clad ultra- high strength steel produced by current process has good bonding properties and can satisfy the GB/T 7734-2015 I demand of flaw detection. The comprehensive mechanical properties of clad steel plate are fine, and there is obvious transition zone in hardness of the joint surface. Both the structure at bonding site and matrix structure are tempered martensite structure.

Key words: Low Alloy Ultra High Strength Steel, Clad Steel Plate, Vacuum Welding, Flaw Detection ,

摘要： 为了开发同时具有超高强度和良好韧性的低合金超高强度钢板,采用30MnCrNiMo连铸坯和33MnCrNi3Mo钢锭,经过真空复合焊接,高温轧制,淬火+低温回火热处理工艺研制出15 mm CrNiMo-CrNi3MoCrNiMo三层复合超高强度钢板;利用探伤、拉伸、冷弯、冲击、硬度等试验检验其结合度和力学性能;利用光学显微镜、扫描电镜等分析三层复合超高强度钢的组织和冲击断口形貌。结果表明,采用该工艺生产的三层复合超高强度钢板结合性良好,能够满足GB/T 7734-2015 Ⅰ级探伤要求;复合钢板的综合力学性能良好,结合面处硬度值存在明显的过渡区域;结合面组织和基体组织均为回火马氏体组织