共查询到19条相似文献,搜索用时 307 毫秒
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实验选用化学腐蚀法预测老化30Cr2MoV汽轮机转子钢的热脆化程度,用苦味酸添加十二烷基苯磺酸钠(SDBS)作为蚀刻液进行化学腐蚀实验.通过正交实验确定较理想实验条件,并在此实验条件下,对12个具有不同韧脆转变温度的试样进行不同温度下的腐蚀实验,找出各温度下晶界宽度参数与FATT50之间的对应关系,确定回归参数,用统计分析软件SPSS对所得数据进行多元线性回归分析,得出老化汽轮机转子钢FATT50的预测模型,经验证明该模型预测精度在±200C之内,精度较高. 相似文献
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管道防腐与维护的综合方法包括:选择适当材质、避免腐蚀的设计、使用涂层和抑制剂等方法、校正流体的化学性质、监测和非破坏性试验及修复。选择什么样的非破坏性试验方法要符合发生腐蚀的形式。地热管道常常发生麻坑状腐蚀点,非破坏性试验的方法应当能够检测出个别的 相似文献
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P92钢时效过程中冲击性能和硬度变化的试验 总被引:3,自引:0,他引:3
对P92钢在650℃下进行了长达10 000 h的时效试验,并研究了时效过程中P92钢的冲击性能和硬度的变化.结果表明:P92钢具有一定程度的热时效脆化倾向,时效初期脆化速度较快,时效500 h时冲击吸收能量约下降50%,随后放缓并逐渐趋于稳定;根据冲击吸收能量与回火参数之间的变化关系,推出600℃下母材和焊缝金属的时效脆化特性,在整个设计寿命内,虽然母材发生一定程度的时效脆化,但冲击韧性仍然较高;焊缝金属在600℃运行5 000 h时即发生很大程度的脆化,冲击韧性较低;P92钢的硬度随时效时间的增加呈下降趋势,但变化不明显. 相似文献
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3.5%Ni—1.7%Cr型转子用钢的回火脆性是由于杂质元素(P、Sn、Sb、Si等)在品界的析聚。表征脆性的塑脆转变温度与品界杂质浓度、硬度和品粒度有关。试验结果表明,在一定条件下,转变温度与上述三因素之间具有简单的线性关系。本文在试验和理论分析基础上,通过包括三个参变量(晶界杂质浓度,硬度和晶粒度)的泰勒级数展开式,导出转变温度计算公式——脆化方程。脆化方程可以用来:(1)计算回火脆化钢的塑脆转变温度;(2)比较各种杂质元素的脆化作用;(3)评价各种元素的有效作用。 相似文献
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为提高电化学动电位再活化法(EPR)检测汽轮机转子钢(30Cr2MoV)热脆性的检测精度,利用Bayesian神经网络建立了预测模型。根据EPR法测定的60组不同苦味酸电解液温度下,30Cr2MoV转子钢的活化峰电流密度与再活化峰电流密度比(Ia/Ir)的数据、电解液温度、转子钢化学成分J参数和晶粒度参数(N),采用Bayesian正则化训练的神经网络,建立了转子钢脆性转变温度(FATT50)与电化学特征值、电解液温度、转子钢化学成分J参数和晶粒度参数(N)之间的映射模型。利用训练好的网络预测了新的转子钢材料的脆性转变温度。结果表明:网络的训练误差和检验误差都在±20℃范围内,小于多元线性回归法得到的误差。因此,Bayesian神经网络能较准确地用来预测转子钢材料的脆性转变温度。图3表3参13 相似文献
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F. Nogata K. Seo
H. Takahashi
K. TamagawaS. H. Chung
《International Journal of Pressure Vessels and Piping》1991,45(3):367-379An etching test using a picric acid solution with a wetting agent was found to have great potential for the nondestructive evaluation of grain boundary embrittlement caused by phosphorus segregation in both CrMo and CrMoV steels, and by carbide or sigma phase precipitation in austenitic stainless steel. A line pipe (CrMo) and a steam turbine rotor (CrMoV) were tested on-site to demonstrate whether the etching test would be a useful tool. The ΔFATT value estimated by the etching test agreed reasonably well with the ΔFATT determined by an electrochemical method for the turbine rotor steel. A good correlation was found between the degree of intergranular corrosion and the material deterioration of SUS316 stainless steel used as a superheater of a fossil fuel boiler. 相似文献
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利用化学镀层对换热面常用的碳钢材料进行表面改性,得到晶胞细致的Ni-Zn-P镀层。将得到的Ni-Zn-P试样与碳钢试样、Ni-P试样进行比较。在黏液形成菌菌悬液中进行微生物污垢和腐蚀实验,进而分析3种试样的抗微生物污垢特性和腐蚀特性。利用称重法记录3种试样的污垢沉积变化情况和光电比浊法记录黏液形成菌的生长情况。利用扫描电镜观察试样在污垢静置实验后的表面形貌,分析比较实验前后表面形貌的变化。利用电化学方法研究试样在黏液形成菌菌悬液中的腐蚀情况。实验结果表明,Ni-Zn-P镀层抗微生物污垢特性和耐腐蚀性稍好于Ni-P镀层,Ni-Zn-P镀层表面微生物污垢附着量相较于Ni-P镀层和碳钢分别减小24.1%和67.7%,Ni-Zn-P镀层表面腐蚀失重量相较于Ni-P镀层和碳钢分别减小5%和84.6%。由于Ni-Zn-P镀层的保护,碳钢表面抗微生物污垢特性和耐腐蚀性得到明显提高。 相似文献
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Kwang Min KimJin Ho Park Jong Hee KimKyoo Young Kim 《International Journal of Hydrogen Energy》2011,36(16):9926-9935
The bipolar plate is an important component of the polymer electrolyte membrane fuel cell (PEMFC) because it supplies the pathway of the electron flow between each unit cell. The ferritic stainless steel is considered a good candidate material for bipolar plate, but it is limited to use as a bipolar plate due to its corrosion problem and high interfacial contact resistance (ICR). To explore a cost-effective method of surface modification, various chemical and heat treatments are performed with 446M ferritic stainless steel to understand the effect of the surface modifications on the ICR and the corrosion resistance. The ICR and corrosion resistance of 446M stainless steel can be effectively controlled by a proper surface modification with combined treatment of immersion in the acidic solution, followed by heat treatment. The combined chemical and heat treatment not only improves the corrosion resistance but also reduces the ICR value. 相似文献
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Longyi Li Jun Wang Jie Xiao Jing Yan Hongyuan Fan Lan Sun Ling Xue Zhenghua Tang 《International Journal of Hydrogen Energy》2021,46(21):11849-11864
As a mature technology, electroless Ni–P alloy coating is widely applied in the protection of chemical equipment and pipelines owing to its excellent corrosion resistance, but its application and long-term service evaluation in the field of high-sulfur oil and gas are rare. Therefore, the time-dependent corrosion behavior of Ni–P coating, which was plated on the L360 steel surface, was investigated in a saturated H2S medium by the method of surface analysis. The results indicate that Ni–P coating with a thickness of about 52.6 μm could significantly reduce the corrosion rate compared with uncoated pipeline steel. This is related to the structure of the dense, protective film on the surface. The uncoated pipeline steel suffered local corrosion during the immersion process, and then it developed into uniform corrosion with the formation of a large number of corrosion products. In comparison, Ni–P coatings corroded relatively mildly with only a thin corroded layer. However, during prolonged corrosion testing, the corrosive medium penetrated the coating/substrate interface at inherent defects, leading to severe local corrosion of the substrate. 相似文献
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