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71.
Long term exposure tests have been carried out on a 3 NiCrMoV steam turbine disc steel in the form of cylindrical tensile test specimens self-loaded to 90% of σ0.2 and exposed to three environmental conditions, viz. deaerated pure water, aerated pure water, and aerated water containing 1.5 ppm of chloride ion. Pitting occurred in all environments but the density and depth of pits in the chloride-containing medium was markedly greater. No cracking was observed in deaerated pure water but cracks initiated in aerated water between 13 and 19 months and in less than 7 months in aerated 1.5 ppm Cl− solution. The probability of a crack initiating from a pit of specific depth in aerated solution could be described well by a Weibull function. Profiling of pits and cracks in the disc steel tested in aerated 1.5 ppm Cl− solution showed that there while there were many cracks with a depth greater than that of the corresponding pit the depth of some cracks was smaller than that of the corresponding pit, suggesting that cracks do not necessarily initiate from the bottom of the pits. The growth rate of short cracks emerging from pits appeared greater than that of long cracks in fracture mechanics specimens. 相似文献
72.
73.
调质状态下40Cr钢的焊接 总被引:1,自引:0,他引:1
在合理制定焊接工艺的基础上,采用R307珠光体耐热钢焊条成功地进行40Cr钢在调质状态下的焊接,解决了通常采用25—13型奥氏体焊条焊接出现的焊缝强度低、焊接接头性能差的问题。 相似文献
74.
A. N. Tugov G. A. Ryabov V. I. Rodionov V. I. Ugnachev A. N. Smirnov V. V. Romanov M. E. Gendel’sman I. B. Kolin 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2006,40(5):300-306
Problems that have arisen during tune-up of the production line for the thermal processing of solid household waste by the
method of burning in a vortical fluidized bed (principally, a new technology for Russia), and means of their solution are
presented. Investigative studies are cited.
__________
Translated from élektricheskie Stantsii, No. 6, pp. 20–26, August, 2006. 相似文献
75.
通过改变高速车削淬火钢(Cr12)的切削用量,对切削力、切削温度、加工表面质量等进行了研究,结果表明合理选择切削用量,高速硬车削淬火钢可显著提高生产率及加工表面质量,并在一定程度上可取代磨削加工。 相似文献
76.
加强电炉钢短流程生产工艺研究与技术开发的建议 总被引:1,自引:0,他引:1
论述了加强电炉钢短流程生产工艺研究与技术开发的必要性和主要课题,并提出关于组织合金钢短流程生产工艺研究与技术开发“九五”国家科技攻关及提高高研究开发投资强度的建议。 相似文献
77.
针对改善催化裂化反应微环境研制开发的DCA - 112催化裂化抑焦剂 ,具有抑制生焦、改善产品分布、应用流程简单、加注方便等特点 ,经中石化长炼分公司 1Mt/a重油催化装置工业应用表明 ,在相近的工艺条件下 ,掺渣比提高 4 13个质量百分点 ,总液收提高 1 0 2个质量百分点。 相似文献
78.
Corrosion behaviour of decorative and wear resistant coatings on steel deposited by reactive magnetron sputtering - Tests and improvements 总被引:1,自引:0,他引:1
Depositions of decorative and wear resistant single layer coatings like TiN, Ti(B,N), CrN, NbN, NbON, (Ti,Mg)N and multilayer coatings like Cr/CrN, Nb/NbN, CrN/NbN and NbN/Nb-C:H were performed using reactive magnetron sputtering. The corrosion behaviour of the coated high speed steel substrates was studied in sodium chloride containing media by open-circuit-potential measurements, potentiodynamic corrosion tests and salt spray tests. Up to now, the best improvements with respect to the corrosion resistance in salt spray tests could be obtained for the system (Ti,Mg)N/high speed steel. 相似文献
79.
Issa S. Oweis 《Canadian Metallurgical Quarterly》2006,132(5):644-650
Approximate closed form solutions are developed for estimating the mechanical and decomposition settlement of landfills. The mechanical settlements are the immediate (primary) settlement and long term creep. The decomposition settlements are generated by mass loss and gas generation. Based on the approximate solution, the decomposition settlement can constitute a significant portion of the total settlement and can be in the same order as the mechanical settlements. Settlement remaining after landfill closure depends on the decomposition environment during filling. For an average decomposition environment, postoperation settlement can still be significant 20?years after completion of filling. 相似文献
80.