共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Mujahid A. K. Lis C. I. Garcia A. J. DeArdo 《Journal of Materials Engineering and Performance》1998,7(2):247-257
The structural steels used in critical construction applications have traditionally been heat-treated low-alloy steels. These
normalized and/or quenched and tempered steels derive strength from their carbon contents. Carbon is a very efficient and
cost-effective element for increasing strength in ferrite-pearlite or tempered martensitic structures, but it is associated
with poor notch toughness. Furthermore, it is well known that both the overall weldability and weldment toughness are inversely
related to the carbon equivalent values, especially at high carbon contents. The stringent control needed for the welding
of these traditional steels is one of the major causes of high fabrication costs.
In order to reduce fabrication cost while simultaneously improving the quality of structural steels, a new family of high-strength
low-alloy steels with copper additions (HSLA-100) has been developed. The alloy design philosophy of the new steels includes
a reduction in the carbon content, which improves toughness and weldability. 相似文献
2.
S. V. Aleksandrov K. Hulka A. M. Stepashin Yu. D. Morozov 《Metal Science and Heat Treatment》2005,47(11-12):497-501
The strength and ductility characteristics, toughness parameters, and structure of low-alloy steels after thermomechanical treatment are studied. Analysis of the properties of steels with various manganese-to-niobium ratios is performed. An optimum chemical composition for sheet steel subjected to thermomechanical treatment is suggested. 相似文献
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We have studied the effect of nitrogen on the cold forging properties of a low carbon steel as a function of temperature. Five AISI 1020 steels with nitrogen contents from 12 to 180 ppm were examined by tensile testing from 25 to 371 °C. Yield strength, tensile elongation (ductility), ultimate tensile strength (UTS), strain hardening exponents and strength coefficients were determined. The influence of nitrogen on the mechanical property behavior of this low carbon steel exhibits trends as expected—when nitrogen content increases, the strength of the steel increases and the ductility decreases. Likewise, as the temperature increases, the strength of the steel generally decreases; however, the ductility initially decreases, then exhibits an increasing trend. Additionally, there is an intermediate temperature range for these alloys where anomalous behavior is observed. Serrated stress–strain curves seen in this temperature range are indicative of dynamic strain aging. It is probable that this anomalous mechanical property trend is due to dynamic strain aging. 相似文献
5.
V. G. Prokoshkina L. M. Kaputkina A. G. Svyazhin 《Metal Science and Heat Treatment》2000,42(10):342-347
Conclusions 1. We have studied the processes of crystallization, the structure, and the thermomechanical hardening of nitrogen-bearing
steels obtained on the base of corrosion-resistant maraging steel. The difference in the cooling rates over the cross section
of the ingot causes a difference in the nitrogen content and the phase composition.
2. The introduction of molybdenum and niobium into the steel increases the concentration of nitrogen in the solid solution
and improves the uniformity of its distribution in the ingot.
3. The use of HTTT for nitrogen-bearing steels is effective; their preliminary heating provides the dissolution of coarse
carbides and carbonitrides, and hot rolling by an optimum regime creates a structure of polygonized austenite with a high
density of subboundaries.
4. The attained level of strength characteristics in the studied steels at an almost fully austonitic structure is 1.5 times
higher than in the traditionally used corrosion-resistant steel. At the same time, the nitrogen-bearing steels preserve a
quite high ductility. The maximum strength of double-phase steels aged after the HTTT is higher than in the base maraging
steel at close ductility values.
Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 10 – 15, September, 2000. 相似文献
6.
Kim Sungjoon 《稀有金属材料与工程》2011,(Z3):1-4
The mechanical properties, microstructure and retained austenite stability of CMnAlSi-TRIP steels were investigated in this paper. The steel sheets were hot-rolled, cold-rolled and heat treated by intercritical annealing and isothermal heat treatment. The microstructure, volume fraction of retained austenite and its carbon concentration were observed by Optical microscopy and X-ray diffraction. The mechanical properties were obtained through uniaxial tensile test. The results show that the CMnAlSi cold-rolled TRIP-aided steels have good combination of strength and ductility with proper isothermal heat treatment, the retained austenite stability determines incremental strain hardening exponent during strain-induced martensitic transformation, and affected by its volume fraction and carbon content. The retained austenite stability has a good correlation with the combination of strength and ductility. 相似文献
7.
随着海洋资源的不断开采和利用,对深海及极地用海洋工程关键部位用钢强韧性等综合性能提出了更高的要求;开发具有更高强塑性,低屈强比,良好的低温韧性、焊接性以及耐腐蚀性等综合性能优良的钢材是海洋工程用钢的发展方向。介绍了国内外低碳低合金海洋工程用钢的研究和发展概况,分析了该类钢种制造过程中面临的问题,对铜在低碳高强钢中的作用以及含铜海洋工程用钢的研发情况进行了综述。 相似文献
8.
Arc welding technology for dissimilar joints 总被引:1,自引:0,他引:1
T Maruyama 《Welding International》2003,17(4):276-281
The most widely used metal underpinning modern industry is steel (carbon steel). Low-alloy steel designed to increase the strength and heat resistance of basic carbon steel and stainless steel to offer improved corrosion resistance and oxidation resistance are extensively used in the manufacture of thermal and nuclear power plants, chemical plants, etc. An extremely important and unavoidable practical requirement in modern steel construction technology is to be able to perform dissimilar welding of stainless steel to carbon and low-alloy steels (welding of dissimilar metals). This article profiles the basic principles and noteworthy features of dissimilar welding of stainless steel to carbon and low-alloy steels. 相似文献
9.
应变速率对低C高Mn TRIP/TWIP钢组织演变和力学行为的影响 总被引:1,自引:0,他引:1
研究了Fe-18Mn低C高Mn TRIP/TWIP钢在应变速率范围为1.67×10-4-103s-1的室温拉伸实验过程中力学性能和组织的变化.在准静态拉伸应变速率范围内(1.67×10-4-1.67×10-1s-1),应变速率对高Mn TRIP/TWIP钢的抗拉强度产生逆效应,随着应变速率的加快,抗拉强度和延伸率都降低;而在动态拉伸应变速率范围内(101-103s-1),应变速率对高Mn TRIP/TWIP钢的延伸率产生逆效应,抗拉强度和延伸率都随着应变速率的加快而增加;在应变速率为103s-1时,高Mn TRIP/TWIP钢抗拉强度可达到957 MPa,延伸率达到55.8%,具有较好的综合力学性能;随着应变速率的提高,马氏体转变量减少,孪生变形向多个方向发展.采用SEM,TEM和XRD等方法对变形前后的组织进行了分析,在所有应变速率范围内的拉伸变形过程中都产生了奥氏体向马氏体转变和形变孪晶,并且在应变速率为103s-1的高速拉伸过程中产生绝热温升效应,使得基体软化. 相似文献
10.
High chromium martensitic steels are designed to provide high corrosion resistance in combination with high strength. Some of these steel grades contain primary carbides for improving the wear resistance, e.g. the steel 440C. The present paper mainly deals with the effect of chemical composition and microstructure on the corrosion properties. Different experimental alloys were produced in the shape of small ingots. The influence of the alloying elements chromium, molybdenum, cobalt, and carbon on the corrosion properties was studied. The results can be summarized as follows: Chromium and molybdenum improve the corrosion resistance, however, only the content of these elements in solid solution in the steel matrix is effective. In case of cobalt the corrosion resistance decreases. The reason is the interaction between cobalt and carbon and its effect on the chromium content in the steel matrix. The calculated pitting resistant equivalent number of high chromium martensitic steels is only limited valid, because there is a major effect of carbide precipitation on the corrosion behaviour. Further investigations were focused on the heat treatment. Especially the effect of the tempering temperature of these steels was studied. The tempering temperature is most relevant for secondary hardening carbide precipitation, which lowers the chromium content of the matrix with detrimental influence on the corrosion properties. The carbide precipitation and chromium distribution was characterized by means of energy filtered transmission electron microscopy (EFTEM). 相似文献
11.
HansBerns BerndEdenhofer RolandZaugg 《材料热处理学报》2004,25(5):354-359
SolNit^R is a novel heat treatment to case harden stainless steels with nitrogen instead of carbon. The calculated equilibrium pressure of N2 corresponds well with the nitrogen content in the steel surface. The process is carried out in vacuum furnaces with pressurized gas quenching. Numerous parts of different stainless steels have been successfully SolNit^R treated in industry leading to superior properties in respect to hardness/strength and corrosion resistance 相似文献
12.
为提升含氮马氏体不锈钢在高温下服役性能,设计了两种试验钢(一种添加0.12%V (质量分数),一种不加V),采用冲击、拉伸试验机、洛氏硬度计、Thermo-Calc软件、OM、SEM、TEM研究了添加微量的V对含氮马氏体不锈钢组织和力学性能的影响。结果表明,在较高温度450~550℃下回火,添加0.12%V较不加V的含氮马氏体不锈钢硬度提高了0.6~1.9 HRC,冲击吸收能量提高了1.2~3.8 J。1050℃淬火、-73℃冷处理、530℃回火后,添加0.12%V钢的塑韧性得到较大提升,断裂方式改变为韧-脆混合断裂,原奥氏体晶粒尺寸由16.48μm减小为11.12μm,未溶第二相的种类和分布由沿着原奥氏体晶界呈断链状分布的短棒状M23C6碳化物转变为弥散分布的球状碳化物和碳氮化物。通过细化晶粒和均匀分布的球状碳化物、碳氮化物,使得含氮马氏体不锈钢的强度和塑韧性均得到提升。 相似文献
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通过在600,630,680,700和720℃保温1 h空冷,以及在630℃短时时效后炉冷和空冷的热处理,研究了不同时效温度、时效时间以及冷却方式对沉淀硬化马氏体不锈钢FV520B的组织和力学性能的影响.结果表明,630℃短时时效后钢中即可析出一定量的逆转变奥氏体,且钢中的析出相尺寸较小并弥散分布,由此提出了一种沉淀强化马氏体不锈钢的热处理工艺优化,即FV520B钢经630℃短时时效并炉冷后.可以获得较佳的高强度和高韧性组合. 相似文献
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O. K. Biswas M. Venkatraman C. S. Narendranath V. P. Deshmukh 《Journal of Materials Engineering and Performance》1992,1(5):651-657
Tempering characteristics of two high-strength low-alloy steels (HY-80 and HX-80) with carbon contents of 0.14 and 0.07%,
respectively, have been investigated by transmission electron microscopic analysis. Mechanical properties such as hardness,
and tensile and impact properties of these two steels were correlated with microstructural features. It was observed that
the major factors contributing to the equivalent strength, better toughness, and weldability of microalloyed HX-80 steel compared
to HY-80 steel include judicious selection of tempering temperature, lower carbon content, and finer grain size. 相似文献
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新型低碳马氏体弹簧钢35SI2CrVB的研究 总被引:1,自引:1,他引:0
传统中、高碳弹簧钢在性能、生产和使用上存在许多缺点,为适应汽车工业发展的需要,研究了碳含量较低的新型低碳马氏体弹簧钢35Si2CrVB。经与传统弹簧钢60Si2MnA相比较,该钢不仅有高的强度、塑韧性,良好的综合力学性能,而且具有低的脱碳敏感性、高的淬透性和高的弹减抗力等。显微组织观察发现,由于35Si2CrVB钢的含碳量降低,其淬火组织发生了变化,几乎全是具有高位错密度的板条状马氏体,而且只有极少量孪晶结构的片状马氏体。 相似文献
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Peng Chen Xin Xu Chao Lin Fuming Yang Jiachen Pang Xiaowu Li Hongliang Yi 《金属学报(英文版)》2022,35(10):1703
A high specific Young’s modulus steel could be achieved by introducing a large fraction of kappa-carbides (κ-carbide), and its ductility was improved by efficiency divorced eutectoid transformation (DET) treatment. For this steel, carbon and aluminum contents affect not only the carbide fraction, but also the type and morphology of carbides, and consequently the mechanical properties. In this work, the alloy was designed by considering both the carbide morphology and Young’s modulus, and the carbides in the high specific Young’s modulus steels were adjusted by controlling carbon content in a suitable range for achieving a good combination of strength and ductility. The detailed microstructure evolution process during DET reaction was studied, and it was found that a higher austenitizing temperature and the cooling rate lower than 300 ℃ h-1 are suitable. The blocky carbides could be avoided by designing the carbon content in a limited content range. The microstructure-property relationship of the experimental steels was also discussed for giving an impetus to the future development of high specific Young’s modulus steels. 相似文献
20.
There exist strong interests of developing nano-grained steels because of the outstanding properties including high strength/weight ratio, wear resistance, excellent toughness, and favorable cellular activity. This article reviews the main fabrication process and microstructural control of nano-structured steels over the last decades. Severe plastic deformation is considered as an effective route of obtaining the nano-grained microstructures. The process of cold-rolling and annealing of martensitic steel is a viable method to obtain bulk nano-structured low carbon steel, while the final thickness of the cold-rolling plate is limited. According to the theoretical results of the thermal simulation studies, a novel alloy design combined with the rapid transformation and rolling process is proposed to successfully fabricate nano-grained high strength bulk steel. The refinement mechanisms are expected to be taking advantage of increase in the transformation nucleation sites and inhibiting the grain coarsening. Moreover, corresponding mechanical properties are summarized. 相似文献