关于18Ni（250级）马氏体时效钢纯度的控制

本文对18Ni(250级)马氏体时效钢的纯度控制进行了研究。指出以双真空工艺冶炼较为合适     

18Ni型马氏体时效钢热挤压管粗晶细化热处理工艺研究

本文较系统地总结了18Ni型马氏体时效钢热挤压管粗晶细化工艺的研究过程。试验结果表明:利用相变成核原理,采取低温循环淬火快速加热方式可克服组织遗传性。晶粒细化的机制在于低温循环加热淬火可增加晶界面积,以及再加热时发生“晶粒边界效应”从而大大提高了奥氏体的成核率。     

18Ni马氏体时效钢晶粒细化的研究

超高强度18Ni马氏体时效钢为国家“七五”攻关项目,其能否安全使用决定于晶粒细化的程度。本文研究和确定了该合金大生产条件下晶粒细化的最佳工艺,晶粒度达ASTM7～8级,保证了该合金研制成功。     

18Ni（300）马氏体时效钢的晶粒细化对拉伸性能的影响

研究了不同的热处理工艺后18Ni（300）马氏体时效铜棒的晶粒度水平,以及在满足技术标准条件下的拉伸性能与晶粒度的关系,找到了获得满足技术标准要求的晶粒度与拉伸性能的18Ni（300）Zh氏体时效钢棒（规格：直径φ≤100mm）的最佳热处理工艺。     

18Ni（200）马氏体时交钢的循环相变晶粒细化新工艺

研究了一种18Ni(200)马氏体时效钢的晶粒细化热处理新工艺。将高温固溶后具有粗大原努奥休氏晶粒的试样在不同温度短时保温，通过金相观察确定再结晶温度点，将试样加热到此点以上不同温度后冷却至室温，进行α=γ循环相变以细化晶粒，结合相变精细微观组织分析，开发出变温循环相变晶粒细化新工艺，达到了较好的细化效果，并较大幅度地提高了18Ni(200)马氏体时效钢的强度和塑性。     

18Ni(200)马氏体时效钢的循环相变晶粒细化新工艺

研究了一种18Ni(200)马氏体时效钢的晶粒细化热处理新工艺。将高温固溶后具有粗大原始奥氏体晶粒的试样在不同温度短时保温,通过金相观察确定再结晶温度点。将试样加热到此点以上不同温度后冷却至室温,进行α′γ循环相变以细化晶粒,结合相变精细微观组织分析,开发出变温循环相变晶粒细化新工艺,达到了较好的细化效果。并较大幅度地提高了18Ni(200)马氏体时效钢的强度和塑性。     

THE PROPERTIES OF 18Ni 350 MARAGING STEEL PRODUCED FROM ELEMENTAL AND PREALLOYED POWDERS

Abstract

The strength of extruded and heat-treated bar of 18Ni 350 maraging steel produced from prealloyed powder has been found to be comparable to that of conventional, wrought 18Ni 350 maraging steel. Impact toughness was considerably higher. In contrast, properties of bar Obtained from an elemental powder mix were markedly inferior to wrought 18Ni 350 maraging steel. The high toughness of Charpy V-notch specimens produced from prealloyed powder was partly attributed to the presence of continuous, aluminium-rich stringers.This resulted in delamination of the specimens during testing and led to a fibrous fracture. Charpy V-notch specimens produced from the elemental powders also contained stringers. However, these were not continuous and therefore did not cause delamination. The resulting fracture surface was flat and relatively featureless. Electron-microprobe analysis has shown that the morphology of the stringers is largely determined by their composition and the composition at the stringer/matrix interface.     

无钴马氏体时效钢的研究进展

本文详细介绍了近年来研制的无钴马氏体时效钢的成分，性能，组织结构特征及应用，为国内开展无钴马氏体时效钢的研究提供了有益的参考。     

时效温度对Fv520(B)钢组织及力学性能的影响

采用高温Ｘ射线衍射、透射电镜等手段研究了Ｆｖ５２０（Ｂ）马氏体沉淀硬化不锈钢经固溶处理＋中间调整处理后不同温度时效处理的显微组织和力学性能。结果表明,４７０℃时效时硬化效率最显著;５２０℃以上时效时,有逆转变奥氏体生成。时效相主要是富铜（ε－Ｃｕ）相、ＮｂＣ、Ｍｏ２Ｃ、Ｍ２３Ｃ６等。６２０℃时效时残余奥氏体量达到最大值,该钢的强度最低;６２０℃以上时效时,发生奥氏体重结晶,残余奥氏体量减少,钢的强     

磷钛微合金化超低碳高强钢的时效强化及力学性能

研究了含微量磷，钛高强钢的时效强化及力学性能，结果表明实验钢具有明显的时效强化效果，时效强化和加工硬化的综合作用可使钢材获得1200MPa的强度和高于10％的伸长率，还可以借助加工工艺参数控制钢材强度和塑性的配合，讨论了这各新型微合金高强度钢的特点，组织与性能变化的规律。     

PROPERTIES OF MARAGING STEEL 300 PRODUCED BY POWDER METALLURGY

Abstract

Powders of 300-grade maraging steel have been produced by two different atomizing processes and consolidated by hot isostatic pressing, extrusion, hot rolling, or a combination of these methods. The tensile properties of the PM alloys were equivalent or superior to those of the conventionally cast and forged alloys, but no improvement in fatigue and fracture-toughness properties was gained. Fine grain sizes (1–5 μm) were obtained by hot rolling either conventionally processed or PM bars of grade-300 maraging steel at 760, 820, and 870°C, followed by air-cooling. In all cases, the tensile properties and fracture toughness were improved by grain-size refinement.     

剪切变形方式对取向硅钢织构和磁性的影响

采用异步轧制将经过一次正常冷轧和中间退火的０．７５ｍｍ厚的工业取向硅钢板材异步轧至不同的厚度,然后进行工业退火,研究剪切变形方式对板材织构和磁性的影响。结果表明：异步轧制下,作用于差轧区上的剪切应力能够有效地改善板材心部的织构组态,并在板材亚表层附近相对较大的区域内形成了理想的冷轧织构;退火后板材内重新形成了取向集中的Ｇｏｓｓ织构,其磁性均不低于常规轧制。     

Fe-Ni-Mo-C粉末锻造钢的综合性能和组织

研究了不同的愿料粉末、Mo含量、不同锻造温度和回火温度对Fe-Ni-Mo-C系粉末锻造钢综合力学性能和组织的影响。由水雾化4600合金粉制得的成分为Fe-2Ni-0.5Mo-0.25C、密度为7.7g/cm~3的粉末锻造钢,经渗碳、淬火、回火后具有最佳综合力学性能,其冲击韧性达32J/cm~2,极限拉伸强度达1280MPa,硬度为HRC53.7。     

半镇静易切钢的工艺特性

对半镇静易切钢与镇静易切钢做了工艺性能比较，用数理统计方法研究了半镇静易切钢的力学性能，并同国家标准、日本及国际标准进行了比较。