国内外弹簧钢生产需求现状及发展趋势

介绍了国内外弹簧钢生产需求的发展现状,重点阐述了我国主要企业弹簧钢生产情况和市场需求,提出了弹簧钢生产及应用的发展方向。     

影响弹簧钢盘条质量的主要因素及控制措施

对弹簧钢盘条在生产过程中存在的问题进行了研究,分析了非金属夹杂物、表面缺陷和脱碳对弹簧钢产品质量的影响,并提出控制措施,为提高弹簧钢盘条的性能和质量提供了解决方向。     

淬火温度对51CrV4弹簧钢组织及性能的影响

研究了51CrV4弹簧钢生产流程中,在相同的均温炉热处理后,工件进入淬火油前的实际温度(淬火温度)对弹簧钢组织及性能的影响。研究结果显示:淬火温度是决定弹簧钢组织及性能的关键因素之一;淬火温度的提升,有助于提高弹簧钢的塑性和延展性,但相应地降低了弹簧钢的强度和硬度。在实际生产中,应根据对产品性能的要求,严格控制淬火温度参数,提高产品性能的一致性。     

低含碳量弹簧钢的研究

一直使用的传统弹簧钢含碳量多在0.50％以上。这类弹簧钢在性能、生产和使用上都存在一些不足。为此研究了含碳量较低的新型弹簧钢。经与传统弹簧钢相比,新弹簧钢具有良好的性能,特别是塑韧性好,综合力学性能好,脱碳倾向低和疲劳寿命高等,对显微组织的观察结果发现,由于含碳量降低,钢的淬火组织发生变化。新弹簧钢中具有高位错密度的条状马氏体量增加,而具有孪晶的片状马氏体量减小。     

高强度弹簧钢的发展现状和趋势分析

我国的现代交通运输行业在不断地发展,运输业是对弹簧钢的需求量最高的行业之一。交通运输业在发展过程中,其对弹簧钢的性能要求也逐渐地提升,提升弹簧钢的强度,促使弹簧钢的寿命增长,这是社会的需要。因此,相关人员已经开展了很多对于弹簧钢的研究工作,以促使我国弹簧钢的产品质量提升。从我国弹簧行业的发展现状以及弹簧钢高强度的研究进展、弹簧钢产品的重点发展方向这几个方面进行阐述,为提升我国弹簧钢的质量提供合理的参考依据。     

钇基稀土对51CrV4弹簧钢组织性能的影响

设计了添加钇基稀土的51CrV4弹簧钢,并借助于单向拉伸试验机,扫描电子显微镜(SEM)以及室温冲击试验机对比分析了钇基稀土对51CrV4弹簧钢组织性能的影响.结果表明,2种弹簧钢的强度和硬度均随回火温度的上升而逐渐下降,而断面收缩率逐渐上升;钇基稀土能明显提高弹簧钢的强度和硬度,尤其是屈服强度,归因于钇基稀土能抑制弹簧钢板条组织特征的形成以及碳化物析出;钇基稀土与弹簧钢中氧、硫形成了细小、均匀分布的稀土氧硫复合夹杂物,可明显改善弹簧钢的冲击韧性.     

减少弹簧钢连铸坯缩孔措施

介绍弹簧钢在方坯连铸机上的浇注实践,通过试验,改进了弹簧钢连铸的生产工艺,解决了弹簧钢连铸坯疏松缩孔等质量问题.     

弹簧钢材质发展综述

根据国内外弹簧钢生产的发展，综述了弹簧钢的化学成分优化、微合金化和稀土处理，新钢种的开发等对弹簧钢性能的影响，以探讨提高弹风的综合性能的途径。     

汽车悬架用弹簧钢55SiCr制备技术的研究进展

悬架弹簧钢是汽车悬架系统的重要部件,研发高性能汽车悬架弹簧钢制备技术对于推动特殊钢材料的国产化有着重要的意义。从洁净度控制、组织性能调控和表面脱碳控制3个方面介绍近年来汽车悬架弹簧钢55SiCr制备技术的最新进展。在洁净度控制上,对弹簧钢中夹杂物的控制方向、脱氧工艺、精炼渣和耐火材料等相关研究进行介绍。在组织性能调控中,重点介绍作者所在研究所在悬架弹簧钢55SiCr热处理工艺改进与优化上的探索,比较了淬火-回火、等温淬火和淬火-配分工艺对悬架弹簧钢55SiCr力学性能的影响。表面脱碳控制的相关研究表明,在进行热处理或热加工的过程中,应尽量避免在低于弹簧钢奥氏体/铁素体转变温度(约800 ℃)附近停留,虽然较高的温度有利于避免全脱碳,但是出于晶粒粗化、能耗和氧化等方面的考虑,热处理温度不宜高于1 100 ℃。     

不锈弹簧钢丝（2）

2不锈弹簧钢丝标准不锈弹簧钢丝现行国家标准及国外标准见表2。在发达国家不锈弹簧钢丝使用范围广泛,在家电、装潢和日用品领域有完全取代碳素弹簧钢丝的趋势。我国不锈弹簧钢丝目前主要用于家用电器,仪表、化工机械和军品等少数领域,年表观消费量仅3万吨左右,相对而言使用牌号比较集中,     

弹簧钢的合金化研究

通用合金弹簧钢是用途最广、最重要的弹簧材料。分析了标准合金弹簧钢的合金化特点及常用合金系列。标准合金弹簧钢使用的合金元素不够广泛，合金系列比较简单，未能充分利用多元合金化的效应。分析和研究了弹簧钢合金化的最新发展趋势。其特点是在更广泛和深入地研究合金元素作用、合金系列及合金化理论的基础上，扩大了合金元素的使用范围，特别是使用了很多以前未曾用过的微量合金元素，发展了大量多元（甚至七元或更多）合金系列，充分利用合金元素的复合合金化效果，明显改善了弹簧钢的性能     

无磁钢的研究概况和我国无磁钢的发展思路

奥氏体无磁钢分为无磁高锰结构钢和无磁不锈钢。无磁高锰结构钢主要应用于电力、交通、建筑等民用领域,无磁不锈钢主要应用于国防军工等高技术领域。分析了Fe-Mn系、Fe-Mn-Cr系和Fe-Mn-Al系无磁高锰结构钢以及无磁不锈钢的国内外发展和研究概况。提出我国开发节约Ni、Mo、Cr等金属资源的减量化高锰无磁钢和高端无磁不锈钢的发展思路,既满足民用领域对无磁钢的力学和无磁性能的需要,又满足国防军工用无磁钢的良好力学、焊接和防腐蚀等综合性能要求。     

METHODS OF EXTENDING THE APPLICABILITY OF SINTERED STEELS

Abstract

It is a common opinion among users of structural parts that applications for sintered steels are limited to those where requirements for strength are low to moderate. Furthermore, sintered steels of moderate strength are thought to be very brittle. It is the object of this paper to draw attention to significant improvements which have been achieved in the last few years. These are basically a result of powder developments which are based partly on traditional alloying additions, such as Cu, Ni, Mo, and C, and partly on unique combinations of iron powders and phosphorus or on combinations of iron powders, phosphorus, carbon, and/or copper. Unusually favourable combinations of strength and ductility can be achieved with diffusion-alloys based on iron and phosphorus. Components of high-duty sintered steels capable of replacing components of conventional wrought steels can be produced from partially prealloyed combinations of iron, copper, nickel, molybdenum, and carbon. For many applications these materials can also be an alternative to powder-forged steels. All the above powder combinations show consistent and low dimensional changes during sintering so that close tolerances of intricately shaped components can be maintained. Material and processing costs are such that the improved properties can be achieved economically.     

海洋平台用钢的研发生产现状与发展趋势

介绍了国内外海洋平台用钢发展现状,总结出海洋平台用钢生产的主要特点,对传统海洋平台用钢的成分、工艺、组织、性能特征及其局限性进行了分析,提出了开发"Mn/C"合金化新型高强韧海洋平台用钢的发展思路,对海洋平台用钢今后的发展趋势加以展望。鉴于我国高级别海洋工程用钢与国外相比仍存在一定的差距,关键产品还依赖于进口,今后应重点研制屈服强度为690 MPa级的海洋平台用高强韧钢。     

Structure and mechanical properties of sintered Ni free structural parts

Abstract

Ni, Cu and in some cases Mo are the alloying elements which have traditionally been used in sintered steels. High performance of powder metallurgy (PM) structural parts from Fe powders is reached mainly by alloying of Ni. The use of Mn in Fe base PM structural parts has been avoided because of its high affinity to oxygen. It is difficult to sinter Mn steel, without oxidation, in industrial atmospheres. However, the PM industry follows also possibilities in order to develop Ni free sintered steels which render as high mechanical properties as diffusion alloyed Ni containing sintered steels and further fulfil the requirements of health protection. In recent years Mn have been introduced as alloying element in Fe based structural parts, on laboratory scale and also for pilot scale production. In this paper the factors that contribute to the structure and mechanical properties of sintered Mn steels are summarised.     

On the structure and properties of high-nitrogen low-carbon non-austenitic steels

Phase transformations, when cooling and heating non-austenitic high-nitrogen low-carbon steels containing chromium and other alloying elements, as well as structure and mechanical properties of these steels were analyzed. It was confirmed that these steels have high temperature chromium diffusion controlled pearlitic type transformation and martensitic type transformation. Experimental high nitrogen steels after quenching and tempering provide mechanical properties of about the same level as high strength commercial alloyed steels. Features of nitrogen as an alloying element in steels discussed allow the supposition of a possible reduction of the consumption of nickel, manganese, molybdenum or tungsten in high strength alloyed steels.     

Paper,honoured with the Sir Charles Hatchett Award by the Institute of Metals,London: Developments in high speed tool steels

This paper describes a research programme at the Austrian School of Mines (Montanuniversität) at Leoben, carried out since 1981 in cooperation with the Max-Planck-Institute for metals research in Stuttgart, on the fundamentals of alloy design for high speed tool steels. Among the results, the development of niobium-alloyed grades has an important place. Controlled solidification studies with a gradient technique have clarified the influence of various alloying elements on the as-cast microstructure of ledeburitic tool steels. A procedure for accurate quantitative metallography in SEM, combined with EDX and STEM-EDX analysis of the chemical compositions of the carbide and matrix phases, has led to a quantitative model for the performance of high speed steels in metal cutting tools, in which the contributions of carbides and of the matrix are combined using empirically determined weight factors. An important role is played by the saturation of the matrix with vanadium and other carbide formers which are essential for secondary hardening. This saturation is related to the way in which these carbide formers are present in the annealed structure; this in turn is influenced decisively by the solidification path (via M₆C or M₂C) of the alloy. On the basis of these concepts, low alloyed, niobium-containing economy grades have been developed whose performance is comparable to that of commercial high speed steels, and perspectives for the development of economic super high speed steels with niobium as an alloying element are indicated.     

Microstructures and mechanical properties of melt-quenched ferritic stainless steels

Using the twin-roller type melt-quenching technique, the effects of rapid solidification on the microstructures and mechanical properties of ferrite have been examined in 17 pct Cr and 17 pct Cr-M steels where M = Ti, Nb, Si, or Al. The melt-quenched 17 pct Cr steels have the columnar and equiaxed grains which become finer with decreasing of specimen thickness. But the yield strength of these steels, which is about 0.48 GPa, remains almost unchanged with grain size refinement, contrary to predictions based on Hall-Petch’s relationship. The columnar structure of the melt-quenched 17 pct Cr-M steels is very fine on alloying with Ti and Si, while it is slightly coarse on alloying with Nb and Al. The hardness, yield strength, and fracture strength of these 17 pct Cr-M steels increase with increased amount of alloying element, these maximum values being about 460 DPN, 1.0 GPa, and 1.35 GPa, respectively, for 17 pct Cr- 6 pct Si steel, in the ductile compositional range. These are suitable values for a fine-gauge material having high hardness and strength as well as good ductility.     

Combined Effects of Nb and B MicroAlloying in Molybdenum Based Ultra Low Carbon Bainitic (ULCB) Steels

ULCB steels have a great potential for structural as well as automotive applications due to the lean alloying concept and the favorable combination of strength and ductility.These steels are being considered as the material of choice for many advanced applications where yield strength above 500 MPa is required to reduce component weight.Traditionally Mo has been a key alloying element in producing such steels.In order to push the property envelope of ULCB steels it is interesting to combine Mo alloying with the microalloying elements Nb and B.Cross effects between these elements bear synergies that cannot be achieved by single alloying.The paper demonstrates how these synergies can be beneficially used in combination with appropriate processing.     

Study on the Corrosion Resistance of Multiphase TRIP Steels

Multiphase TRIP (Transformation Induced Plasticity) steels are known to combine higher strength with higher ductility.In this paper,the corrosion resistance of this steel has been has been investigated by accelerated corrosion tests,such as wet/dry cyclic corrosion and the weight loss in laboratory.The morphologies of their rust layers were observed by using scanning electron microscopy,and the corrosion performance of these steels was discussed by analyzing the protective mechanism.The results show that the corrosion rate of steel A is significantly greater than that of steels B and C in wet/dry cyclic corrosion and weight loss tests.The corrosion performance of conventional C-Mn-Si TRIP steel is deteriorated in both NaHSO 3 and 3.5 wt.% NaCl aqueous solutions.And superior corrosion performance is exhibited for TRIP steel with low alloying contents due to its high thermodynamic stability.The enhancement of corrosion performance of TRIP steel is attributed to the additions of alloying elements,such as Al,Cu,Cr,Mo,Ni,etc.The alloying elements increase the compactness of rust layers,so electrochemical characteristic of TRIP steel is improved.