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21/4Cr1Mo钢的高温疲劳裂纹扩展行为研究 总被引:2,自引:0,他引:2
对 2 14 Cr1 Mo钢在常温、 2 0 0℃、 42 0℃和 50 0℃下的疲劳裂纹扩展速率进行测试和分析 ,得到四种温度下的疲劳裂纹扩展规律 ;并从机械力学性能和疲劳断口两个方面分析 2 14 Cr1 Mo钢随温度变化的疲劳裂纹扩展速率的变化机理 相似文献
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对2.25C r1M o和2.25C r1M oV钢在常温到500℃的温度区间内的多个温度上进行疲劳裂纹扩展速率测试和分析,对疲劳断口形貌进行观察,得到了两种材料的高温疲劳裂纹扩展规律。结果表明:两种材料高温下疲劳裂纹扩展规律基本一致;裂纹扩展速率随着温度的升高而增大;疲劳裂纹扩展方式由穿晶型为主向沿晶型为主转变。 相似文献
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主要研究了涡轮盘用GH169镍基高温合金,在360、550、650℃下的低周疲劳裂纹扩展特性;650℃时,保持时间对疲劳裂纹扩展速率(da/dN)的影响;并且利用扫描电镜(SEM)对断口形貌进行了分析。 相似文献
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首先进行了16Mn板材半椭圆表面裂纹疲劳扩展试验。试验结果表明,采用Newman-raju应力强度因子时,表面裂纹深度方向和表面方向的扩展速率均符合Paris公式。在此基础上,从Newman-Raju应力强度因子计算式和Paris疲劳裂纹扩展速率公式出发,通过理论和数值分析,建立了3类表面裂纹在受拉伸、弯曲、和拉弯组合加载下的疲劳扩展形貌统一表达式,并通过疲劳试验结果对其进行了考核。结果表明,采用统一表达式预测裂纹形貌的各项统计指标均优于其他两种表达式 相似文献
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通过对无预裂纹圆柱形缺口试件的常温、高温低周疲劳总寿命试验以及对带有预裂纹圆柱形缺口试件的常温、高温裂纹扩展寿命试验,并利用NHRDS有限元程序进行了缺口附近轴对称问题的循环应力和应变计算,研究了非均匀分布复杂应力状态下低周疲劳寿命。结果表明,2 .25Cr 1Mo 材料复杂应力状态下低周疲劳总寿命和裂纹扩展寿命可采用当量形式的Manson Coffin 公式进行表征。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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杀虫磺缓释剂杀钉螺试验报告 总被引:1,自引:0,他引:1
杀虫磺缓释剂浸杀成螺、幼螺、螺卵效果好,现场应用缓释片63克/米^2,半年后活螺平均密度下降93.2%,春季施药1次,可达到控制当年钉螺的扩散。 相似文献
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为实时监控化学-酶法制备氰氟草酯反应过程,建立了一种该体系中氰氟草酯的RP-HPLC的检测方法。采用SymmetryC18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇)∶V(水)=80∶20为流动相,流速为1.0 mL/min,紫外检测波长为282 nm,柱温为30℃,进样量为20μL。氰氟草酯在5.0~1000.0 mg/L范围内线性良好,相关系数达到0.9999,检出限为1.0 mg/L,相对标准偏差为0.58%(n=5),加标回收率在92.3%~101.5%之间。 相似文献