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当代合金结构钢的发展 总被引:1,自引:0,他引:1
本文根据欧美和日本近20年合金结构钢的发展,论了近代合金化及冶金及冶金工艺技术进展对高强度低合金钢,渗碳钢-齿轮钢,非调质钢广泛应用的影响。 相似文献
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日本高强度齿轮钢的现状,最显著的特点:①采用提高压缩残余应力的方法,来提高耐疲劳强度的性能。②降低Si等元素含量,减少渗碳时的内部氧化。③合金成份的设计喷丸处理相结合,以提高齿轮的强度。下面介绍日本六家钢铁厂生产的高强度齿轮钢的情 相似文献
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该文阐述高强度渗碳齿轮钢17Cr2Ni2Mo的研制工艺、检测结果及技术指标,达到并超过西德DIN1710标准。 相似文献
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《Baosteel Technical Research》2010,(Z1):73
Demand of improving the mechanical properties and productivity of automotive components while minimizing environmental impact makes the development of special steel combined with advance heat treatment and surface modification technologies become an important research area. Recently,to reduce CO2 emissions by saving the manufacturing time,the following new special steel and advance heat treatment methods were developed: (1 ) An anti-coarsening extra-fine case hardening steel for automobile gear was developed,whose carburizing temperature can be improved for conventional 930 - 950℃to 1 050℃without coarsening,and the carburizing time can be reduced by maximum 75%. (2) Various microalloyed steels for fracture splitting connecting rod were developed.By using the above-mentioned steel combined with Thermo Mechanical Control Process(TMCP) method,the manufacturing time can be reduced by 30%-40%. (3) Vacuum carburizing and mild carburizing combined with induction quenching are being developed to replace the traditional gas carburizing,and the CO2 emissions can be reduced by 20%-40%. (4) Intensive quenching is another new quenching technology which can be defined as cooling usually with pure water quenchant or low concentration water/salt solutions at a rate several times higher than the rate of " normal" or conventional quenching,and the conventional effective case hardening depth can be reduce greatly and carburizing time can reduced. In addition,the high pressure gas quenching for reducing the quenching distortion and dual shot-peening for improving fatigue strength of gear will also be discussed. In a word,the present paper will focus on how to use the interaction among the development of special steel, advance heat treatment and surface modification to improve the strength of automotive components while reducing the manufacturing cost and impact to environment. 相似文献
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摘要:通过Nb微合金化提高渗碳温度是当前发展高端齿轮钢的重要思路。以20Cr钢为基准成分,通过实验室熔炼、锻造以及977~1134℃范围内高温伪渗碳实验,研究了0.02%、0.04%、0.06%、0.08%等不同Nb质量分数下渗碳后的奥氏体晶粒结构。在此基础上,依据热力学计算及析出颗粒熟化模型,对AlN、Nb(C,N)颗粒的钉扎强度进行估算并与晶粒尺寸建立联系,得到了适用于含Al、Nb齿轮钢的奥氏体晶粒度控制预测模型。最后,依据此模型分析了Nb含量对20Cr钢渗碳温度的影响,并基于高温渗碳目标提出了Nb微合金化的成分建议。 相似文献
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粉末锻造(粉锻)技术结合了粉末冶金技术和精密锻造技术的优点,对烧结的预压件进行一次锻打即可生产出精度高、力学性能强的近净成形产品。本文选择一款齿轮材料(Q61),通过压制、脱脂、烧结工艺获得标准块预压件,然后进行闭模热锻获得致密的标准块。对标准块进行物理性能(密度、硬度、拉伸性能、疲劳性能等)测试和微观组织表征。结果表明,获得的Q61粉锻标准块基本完全致密,密度为7.87 g·cm^-3;空冷硬度约为HRC 25.3,淬火硬度约为HRC 62.1,空冷态较低的硬度为零件后续机加工、整形提供了保证,后续淬火获得的高硬度可节省渗碳工序;标准块抗拉强度达到1052.8 MPa,可与常用齿轮钢性能媲美。本文采用粉锻技术,成功制备出高质量行星直齿轮,其齿部高频淬火后硬度与渗碳齿轮的硬度相当。该工作为粉末锻造技术在我国工业界的发展提供了有益的探索。 相似文献
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The potential is considered for use of microalloyed bar steels,in conjunction with thermomechanical processing,to enhance the properties of steels heat treated at higher process temperatures than have been used historically.Two examples are highlighted:microalloyed spring steels with enhanced resistance to tempering and Nb-modified gear steels for high temperature vacuum carburizing,e.g.on the order of 1050℃ versus 930℃ for a typical gas carburizing operation.In the spring steel example,the Nb+V steel results in significantly finer prior austenite grain sizes than the other steels considered,enhanced fatigue performance,and improved toughness.In the Nb-modified carburizing steel,Nb additions up to 0.1 wt pct to a Ti-modified 8620 steel,in conjunction with thermomechanical processing to control initial precipitate distributions prior to carburizing,are shown to lead to materials with improved resistance to abnormal austenitic grain growth at the higher process temperatures.Alloy content and heating rate to the carburizing temperature were shown to be important variables and suppression of abnormal grain growth was correlated with the development of a critical distribution of fine NbC precipitates,stable at the austenitizing temperature leading to improved fatigue performance in steels with fine and uniform grain structures.Opportunities for extending the results of this study to alloy design and controlled rolling in bar mills are assessed. 相似文献
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In the last decade, the European niobium consumption in automotive strip and sheet has more than tripled. The development of high strength and advanced high strength steel grades for strip and plate products focused upon constantly increasing strength levels combined with excellent fatigue properties as well as formability and weldability. Until now, the high potential of microalloyed steel has not been used to the same extent in forgings and springs. This paper reviews automotive components as transmissions, suspensions and springs highlighting new material solutions for special steels having optimized processing and in‐use properties. Special consideration is given to the metallurgical background as well as to examples for the processing and application of niobium microalloyed steel in forgings and springs from low carbon and higher carbon containing steels. Niobium metallurgy permits the reduction of carbon to meet more stringent end‐user requirements demanding high strength combined with improved toughness, fatigue strength and weldability at a competitive manufacturing cost. 相似文献
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《Baosteel Technical Research》2010,(Z1):85
Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is driven by tougher working conditions,higher efficiency,environment consideration,resource limitation and cost reduction. This presentation will focus on the development of ultra high strength special steels and wrought Ni-base superalloys in aircraft industry. The examples of ultra-high strength steels include: (1) Ultra-high strength stainless steels for landing gear and other structures; (2)High speed and high temperature main shaft bearing steels; (3) Ultra-high strength steels for jet engine main shaft. New and modified Ni-base superalloys will be discussed by examples of (1 )Low cost,process-friendly superalloys with higher performance; (2)Modification of hard-to-processed superalloys. Future development of those materials will be addressed. 相似文献
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轻量化且高强韧化已成为汽车用钢的主要发展方向。在不同类型的轻质钢中,Fe-Mn-Al-C系奥氏体基低密度钢因具有更高的比强度和良好的塑韧性备受研究者们青睐。从成分体系与力学性能、多种强韧化机制、不同变形机制及工艺调控等方面总结了Fe-Mn-Al-C系奥氏体基低密度钢的研究进展,重点阐述了奥氏体基低密度钢中特有的B2相以及κ-碳化物、MC碳化物等析出相的析出行为对强韧性机制的影响。最后,结合目前国内外学者对Fe-Mn-Al-C系奥氏体基低密度钢的最新研究成果,对奥氏体基低密度钢进行了展望。 相似文献
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以排气系统为中心,介绍了国内外超纯铁素体不锈钢的开发和应用现状,并对我国超纯铁素体不锈钢的生产和发展进行了展望。 相似文献