共查询到19条相似文献,搜索用时 250 毫秒
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系统研究了V、Mo、Mn合金元素的添加及热处理工艺参数对Cr-Mo低合金气瓶钢性能的影响。研究发现,540℃回火时添加0.13%的V元素可使合金强度提高60 MPa,材料强度的提高主要来源于晶粒组织的细化。随回火温度的升高,材料强度线性降低,但添加V的合金具有更好的回火稳定性。进一步增加合金Mo元素含量,其抗拉强度在570℃回火时达到峰值1 245 MPa,600℃回火时样品强度达到1 185 MPa,-50℃低温冲击韧性为52 J/cm2,具有良好的强韧性配合。Mn元素虽然也有利于提高材料强度,但样品冲击韧性一直处于较低值。 相似文献
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自回火温度对20MnSi钢筋组织及力学性能影响 总被引:1,自引:0,他引:1
对不同合金成分20MnSi钢进行控轧控冷和不同温度自回火处理后,分别采用光学显微镜和多功能材料试验机研究了不同自回火温度下不同硅、锰含量20MnSi钢筋的显微组织及力学性能。试验结果表明:随着自回火温度的升高,钢筋的表层显微组织逐渐得到改善,并最终得到珠光体组织,使20MnSi钢筋的强度与韧性得到良好配合; 20MnSi钢筋的淬透性随钢筋中Si、Mn元素含量的提高而提高,从而显著增强钢筋的力学性能。采用控轧控冷工艺,在标准范围内适当提高硅、锰含量,并在轧后进行高温自回火,可在不额外加入Nb、V等微合金元素的基础上进行HRB400钢筋的生产。 相似文献
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进行了有关强化控制轧制与加速冷却钢的冶金分析。与普通轧制相比较,采用加速冷却可强化具有铁素体-珠光体组织结构的低碳当量钢。这种强化来源于:①细微的铁素体晶粒;②铁素体自身强化;⑧珠光体体积百分率提高。而铁素体强化起因于铁素体的过饱和、细微弥散的碳化物以及铁素体晶粒位错诱导相变。此外,还对具有马氏体组织结构合金钢直接淬火后的强度进行了研究。在淬火工艺条件方面,将钢从非奥氏体再结晶区进行直接淬火与相同成分的加热-淬火钢相比,具有更高的强度。显然,这并非取决于钢材中的合金元素,而是由所保留的热轧马氏体引起晶格缺陷所决定。然而,与普通淬火钢水平相比较,回火后直接淬火钢的强化则受合金元素的影响。在直接淬火钢回火以及奥氏体区加工时,钼是最有效的合金元素,因其与抑制回火时位错消失密切相关。 相似文献
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众所周知,具有低的C含量的贝氏体钢可以获得优良的强韧综合性能,主要原因是极低的C含量能降低或消除了贝氏铁素基体中的渗C体,因此钢的韧性能得到进一步的改善。为了保证贝氏体转变的淬透性良好,而马氏体转变的淬透性相对较低,应该适量添加其它合金元素。大量的研 相似文献
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具有铁素体加回火马氏体两相组织的高铬合金强度高、韧性好,同时抗腐蚀性能优良,在油气开采领域具有广阔的应用前景。研究N、Cu、Mo、Nb、Ni、Cr元素含量对合金组织组成、力学性能影响,结果显示,降低N和Cu元素含量将使双相钢中铁素体比例提高,导致两相界面增大,使材料低温冲击韧性降低。Mo含量下降将使材料强度降低,少量Nb元素的添加对合金强度提高作用不明显。提高合金中Ni、N、Cr、Mo元素含量将使奥氏体保持到室温下,材料组织转变为铁素体加奥氏体两相组织,材料屈服强度低于500 MPa。高温应力—应变曲线检测结果显示,双相合金在1 100~1 200℃范围内变形抗力较小,但轧制过程中易在铁素体、奥氏体两相界面处产生裂纹。 相似文献
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详细研究了奥氏体化温度对中碳调质钢40CrNiMo的淬透性、以0.7 ℃/s淬火后组织及调质处理后组织和性能的影响。研究结果显示,随着奥氏体化温度从800提高至1 000 ℃,材料的淬透性逐渐增加,尤其是当奥氏体化温度提高至950 ℃以后,淬透性增加幅度显著变大。当奥氏体化温度为800 ℃时,组织中存在相对多的铁素体,使得淬火后材料的硬度较低,但回火后具有最佳的韧性;奥氏体化温度为900 ℃时,高温回火后试样具有最高的强度,但塑性较低。随着奥氏体化温度的升高,材料的断裂机制发生明显变化,拉伸断裂均为典型韧性断裂,断口均为韧窝组成,而冲击断裂逐渐由韧窝断裂方式转变为解理或准解理断裂方式,当奥氏体化温度超过900 ℃后,断口形貌以典型河流花样为主。 相似文献
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为改进调质态超高强海洋工程用钢的力学性能,研究了2炉不同硼含量的钢。经控制轧制后,在实验室条件下采用不同回火温度处理以确定最佳热处理温度,并对实验钢板进行金相组织观察,利用扫描电镜和透射电镜讨论分析了硼及回火温度对组织、性能的影响。实验结果表明,硼有利于提高钢板的淬透性,含硼钢600℃回火可以满足E690的性能要求;随回火温度的提高,含硼钢和无硼钢的强度降低,伸长率升高,含硼钢的变化幅度比无硼钢大;含硼钢在630~660℃存在明显的回火脆性区,而无硼钢具有较好的回火稳定性;无硼钢在650℃回火可以满足E550的性能要求。 相似文献
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分别采用VN、Fe—V合金在实验室冶炼了不同钒含量的Si—Mn系弹簧钢,并系统研究了其淬透性、抗回火稳定性、表面脱碳敏感性和力学性能的变化情况。结果表明,本试验条件下,采用钒氮微合金化的Si—Mn系弹簧钢(0.50%C,0.06%-0.10%V,0.01%N)具有较好的淬透性和抗回火稳定性。钒含量增加,强度显著增加。钒氮微合金化对表面脱碳敏感性没有明显影响。 相似文献
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D. V. Ovchinnikov O. A. Sofrygina S. Yu. Zhukova I. Yu. Pyshmintsev S. M. Bityukov 《Steel in Translation》2011,41(4):356-360
Microalloying with boron (up to 0.005%) has a considerable influence on the hardenability of steel. Four alloying systems
with complete and partial replacement of molybdenum by microadditions of boron are studied. The resulting mechanical properties
are satisfactory for high-strength pipe corresponding to strength groups from N80 (type Q) to Q135, according to the API 5CT,
ISO 11960, and GOST R 53366 standards. The reversible tempering brittleness of Nb-B steel and Mo-B steel is considered. Overall,
the strength and impact strength of Mo-B steel are greater than for steel without molybdenum. 相似文献
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V. V. Pavlov L. A. Godik L. V. Korneva N. A. Kozyrev E. P. Kuznetsov 《Metallurgist》2007,51(3-4):209-212
Results are presented from a study of the mechanical characteristics and microstructure of rails made at the Novokuznetsk
Metallurgical Combine from steel alloyed with manganese, silicon, chromium, molybdenum, and vanadium. It was established that
obtaining high strength and hardness in the steel by increasing its contents of carbon and alloying elements has an adverse
effect on the service properties of rails made of steels with a bainitic structure. Normalizing is the most effective means
of increasing strength and improving microstructure. The required level of mechanical characteristics can be obtained by tempering
the steel at 350–370°C. The adverse effect of cold straightening-which is manifest in a reduction in the rails’s impact toughness-can
be offset by subjecting the steel to preliminary tempering or normalizing and tempering. Rather than further increasing the
strength of rail steel to improve its overall quality, this objective is better served by making sure that the steel is cleanly
made, that the rails have little or no curvature, and that the residual stresses in the steel are favorably distributed.
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Translated from Metallurg, No. 4, pp. 51–53, April, 2007. 相似文献
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Two medium carbon low-alloy MnSiCrB cast steels containing different Cu contents (0.01 wt pct and 0.62 wt pct) were designed,
and the effect of Cu on the mechanical properties and corrosion–abrasion wear behavior of the cast steels was studied. The
results showed that the low-alloy MnSiCrB cast steels obtained excellent hardenability by a cheap alloying scheme. The microstructure
of the MnSiCrB cast steels after water quenching from 1123 K (850 °C) consists of lath martensite and retained austenite.
After tempering at 503 K (230 °C), carbides precipitated, and the hardness of the cast steels reached 51 to 52 HRC. The addition
of Cu was detrimental to the ductility and impact toughness but was beneficial to the wear resistance in a corrosion–abrasion
wear test. The MnSiCrB cast steel with Cu by the simple alloying scheme and heat treatment has the advantages of being high
performance, low cost, and environmentally friendly. It is a potential, advanced wear-resistant cast steel for corrosion–abrasion
wear conditions. 相似文献
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Hardenabilityisanimportantpropertyforlargeandmedium-sizehot-forgingdiesteels.Themainreasonwhythelarge-sizediesmadeofthegeneralhot-forgingdiesteel5CrNiMohaveshortlifeisthelowerhardenabilityofthesteel.Inordertoincreasetheservicelife,aseriesofdeep-hardeningsteels,suchas4Cr2MoVNi,3Cr2WMoVNiand4CrMnSiMoV,weredevelopedinChina.Butthedifferenceofhardenabilityamongthesesteelscan′tbedeterminedbythestandardJominytestbecausetheirJominycurveshavenodrops.Meanwhile,it′sverydifficulttodissectarealqu… 相似文献