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《铸造技术》2016,(9):1818-1820
研究了添加微量元素V的方法改善20MnSiⅡ建筑工程用钢的力学性能。采用真空冶炼炉对钒铁、氮化锰和氮化硅锰等进行冶炼后,对得到的钢样进行热处理,从而得到目标钢样。当V的含量分别为0.015%、0.025%、0.04%、0.05%,钢样的平均晶粒尺寸分别为8.2、5.5、3.4、1.5μm;随着钒元素含量的增加,晶粒尺寸依次减小,晶粒得到细化。屈服强度和抗拉强度与钒含量关系曲线呈抛物线,在V的含量为0.04%时,屈服强度和抗拉强度出现最大值,分别为886 MPa和1055 MPa;伸长率随着钒含量的增加一直呈增大趋势,伸长率最大可达23.4%。室温下的钢样冲击功最大可达99.8 J。改善后钢样的力学性能满足国家标准GB50204-2002《混凝土结构工程质量验收规范》。 相似文献
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分别测试了新型F级船用低温钢板表面生成不同氧化物后的往复摩擦行为,并结合白光干涉仪以及扫描电子显微镜分别对钢样的显微组织形貌和磨痕形貌进行了表征.结果 表明:γ-FeOOH氧化层钢样、原始钢样、Fe3O4氧化层钢样的耐磨蚀性能依次变高.其中,致密完整的Fe3O4氧化层钢样的磨损量最低,磨痕轮廓深度和尺寸都最小,表面以粘... 相似文献
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南海榆林海域环境因素对钢局部腐蚀的影响 总被引:3,自引:0,他引:3
采用典型钢宏观海生物实海验征腐蚀试验,测试分析钢样锈层中主要腐蚀细菌、FeS和钙盐沉淀物.结果表明,由于南海榆林海域水温较高,海生物一年四季生长旺盛,在钢样表面呈不均匀附着,使钢样表面电化学不均匀性增大;榆林站钢样锈层中几种好氧菌及厌氧的硫酸盐还原菌比温度较低的青岛站的高几倍至3个数量级,并呈聚集分布;几种钢样腐蚀产物中的Fes含量榆林比青岛高0.1~1倍左右,南海榆林海域细菌局部腐蚀效应较大,这是加剧钢的局部腐蚀的两个重要因素. 相似文献
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对偶氮胂Ⅲ测定钢中铬进行了显色反应条件的选择,消除了铝、稀土、钼的干扰影响,络合物最大吸收波长在630μm处,铬量在4~60μg/50 ml符合比尔定律,用于各种钢样中铬含量的测定,结果令人满意. 相似文献
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不同碳纤维表面状态及其复合材料界面对比 总被引:1,自引:0,他引:1
对比研究了进口T300碳纤维和国产JC2#纤维的表面状态及其在C/SiC复合材料中形成的界面状态。结果显示T300纤维表面。和N杂原子含量丰富,其C原子含量仅为86.0%;而JC2#纤维的表面C原子含量达到93%。与JC2#纤维相比,T300纤维的表面更为粗糙,其表面沟槽粗壮杂乱。在C/SiC复合材料中,T300纤维与SiC基体紧密结合,经界面微脱粘法测试得出T300纤维与基体的界面微脱粘载荷是JC2#纤维的2倍。高表面活性和粗糙物理表面是T300纤维在C/SiC复合材料中形成强界面结合的根本原因。 相似文献
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立体钢样仓库具有控制方式灵活,控制简单,实时性强及成本低等优点,而基于组态王的监控系统可以实现钢样的可视化和准确控制.文章依据企业所提立体钢样仓库的存储要求,搭建出一种基于传感器系统、组态系统、PLC系统的硬件平台,采用磁栅尺(SIKO)测高模块,接近开关(LJ12A3-4-Z/BX)限位模块,设计了基于组态王的监测系统,该系统可对立体仓库中运动小车的高度数据进行实时的监测采集,实现实时准确存储. 相似文献
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Rapid solidification is regarded as being an effective method to refine the microstructure and reduce or eliminate the segregation of alloying elements.In this study the microstructures of rapid solidified carbon steel droplets (cooled in silicone oil) with different C contents by drop tube processing were observed.The volumes of droplets were set to be 2 mm×2 mm×2 mm (TM) and 5 mm×5 mm×5 mm (FM).For most samples,the microstructures are nearly the same from the surface to the center region.The microstructures of the FM samples with higher C content are much finer than those of the TM samples,which is the opposite of the situation with the lower C content samples.The distribution of C along the diameter of each sample was detected.The segregation of C was observed in TM samples with higher C contents while not in FM samples.This is regarded as relating to recalescence and the diffusion of C atoms during the solidification process. 相似文献
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借助于X射线衍射,研究了C、Mn、Cr和Ni 含量对304奥氏体不锈钢拉伸力学性能和应变诱发 马氏体相变倾向的影响。结果表明:C、Mn、Cr和Ni在允许的成分范围内变化,应变诱发α′马氏体相变倾向差异很大,这导致屈服强度和抗拉强度复杂的变化,尽管应变诱发α′马氏体相变使加工硬化速率提高,相变可以诱发塑性,但相变速率较快,相变倾向较大的钢塑性反而下降,此外,由于室温变形还增大热诱发马氏体相变倾向,从而限制了C、Mn、Cr和Ni下限钢在高精度和低温环境下构件的应用。 相似文献
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研究了C和Nb含量对TP347HFG钢在650℃析出相参量(成分、体积分数和尺寸)和持久寿命的影响.对ASME成分范围内的2种不同C和Nb含量的TP347HFG钢在650℃,230和150 MPa条件下进行持久实验,持久寿命分别为199,420 h和2426,8837 h,其中C含量较低Nb含量较高的样品持久寿命较长.对持久管样的EPMA-EDS+MPSM和TEM-EDS分析表明,较低的C含量和较高的Nb含量对应较少的M23C6和较多的MX,并阻碍了M23C6的聚集粗化,同时基体中可保留较多的Cr,有利于延长持久寿命.此外,运用热力学软件Thermo-Calc分析了在500—1300℃范围内C和Nb组合含量的变化对各相成分和体积分数的影响,与实验结果相吻合. 相似文献
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借助于C射线衍射,研究了C、Mn、Cr和Ni含量对304奥氏体不锈钢拉伸力学性能和应变诱发马氏体相变倾向的影响。结果表明:C、Mn、Cr和Ni在允许的成分范围内变化,应变诱发α’马氏体相变倾向差异很大,这导致屈服强度和抗拉强度复杂的变化,尽管应变诱发α’马氏体相变使加工硬化速率提高,相变可以诱发塑性,但相变速率较快,相变倾向较大的钢塑性反而下降,此外,由于室温变形还增大热诱发马氏体相变倾向,从而限制了C、Mn、Cr和Ni下限钢在高精度和低温环境下构件的应用。 相似文献
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研究了C和Nb含量对TP347HFG钢在650℃析出相参量(成分、体积分数和尺寸)和持久寿命的影响.对ASME成分范围内的2种不同C和Nb含量的TP347HFG钢在650℃,230和150 MPa条件下进行持久实验,持久寿命分别为199,420 h和2426,8837 h,其中C含量较低Nb含量较高的样品持久寿命较长.对持久管样的EPMA-EDS+MPSM和TEM-EDS分析表明,较低的C含量和较高的Nb含量对应较少的M23C6和较多的MX,并阻碍了M23C6的聚集粗化,同时基体中可保留较多的Cr,有利于延长持久寿命.此外,运用热力学软件Thermo-Calc分析了在500-1300℃范围内C和Nb组合含量的变化对各相成分和体积分数的影响,与实验结果相吻合. 相似文献
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Bruno Geoffroy Scuracchio Cláudio Geraldo Sch?n 《Journal of Phase Equilibria and Diffusion》2012,33(2):115-120
The influence of different Cr and C contents upon the solidification interval of ASTM A352M-06 Grade CA6NM cast martensitic
stainless steel has been investigated using computational thermodynamics, and checked against DTA measurements in samples
taken from 13 large cast parts, in order to identify potential sources for improvement on the part castability. Calculation
results suggest, indeed, that this would be the case for C: when its content increases from 0.018 to 0.044 wt.% C (within
the allowed range in the alloy specification), the solidification intervals increases from 25 to 43 K, which suggests improved
castability with decreasing C contents. DTA results, however, do not support this prediction, showing a fairly constant solidification
interval around 23 K for all investigated samples. The results are discussed both regarding the impact in alloy processing
and the fitness of the existing databases to reproduce experimental results in these limiting cases. 相似文献
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借助于X射线衍射技术,研究了304亚稳奥氏体不锈钢应变诱发马氏体相变倾向对化学成分的敏感性。液氮温度拉伸结果表明:C、Mn、Cr和Ni从标准范围的上限变化到下限,马氏体相变倾向显著增大,加工硬化明显提高。应变诱发α′马氏体相变倾向对C、Mn、Cr和Ni含量很敏感,要控制马氏体相变的发生,可通过优化C、Mn、Cr和Ni含量来实现。 相似文献
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Ming-chen Ma Chao-qing Luo Si-min Chen Hong-qun Tang Shan-shan Hu Yu-mei Zhou Jian-lin Liang 《中国铸造》2022,19(2):169-176
Boron and carbon contents are the main factors influencing the properties of high-boron steel.In this study,experimental samples with different boron-to-carbon ratios(%B/%C)were prepared.The microstructures of the different samples were observed,and their hardness,bending strength,and impact toughness were investigated.Results show that the main microstructures in the investigated high-boron steel samples are the eutectic Fe2B structure with a fishbone shape and the ternary peritectic Fe3(C,B)structure with a chrysanthemum shape.When the boron content is 2.5wt.%and the carbon content is 0.43wt.%(i.e.,%B/%C=5.82),the overall mechanical properties of the alloy are the best.The alloy's hardness,bending strength and impact toughness reach their maximums,which are 67.3 HRC,1,267.36 MPa and 6.19 J·cm-2,respectively.The optimized alloy is compared with conventional materials exhibiting excellent wear resistance(namely,high-manganese steel and high-chromium cast iron)through two-body and three-body abrasion tests.The wear resistance of this high-boron steelinvestigated in this work is found to be superior to those of the more common materials. 相似文献
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Properties of the weldable and corrosion resistant steel X 2 CrNiMoN 25 22 In view of the limited application of con- ventional CrNiMo steels the authors have investigated potential applications of the above mentioned steel. An optimum com- position would be (%) 0.02 C, 25Cr, 22 Ni, 2 Mo and 0.1 N. The low carbon content is a vital factor and the nickel content must not exceed 22% because higher contents would give rise to very pronounced precipitation. The new steel ist largely resistance to boil- ing nitric acid it is considerably superior to conventional steels, The high break-through potential is indicative of high pitting resist- ance. Improvements are equally remarkable with respect to mecanical properties and weldability 相似文献