共查询到19条相似文献,搜索用时 156 毫秒
1.
2.
3.
4.
5.
由中国航空工业总公司提出、625所、410厂和430厂的马翔生等人主要负责起草的航空工业标准《高温合全、不锈钢真空电子束焊接工艺》于1998年6月26日发布,1998年7月1日实施,标准号为HB7315-1998.该标准是根据航空制造技术特点及质量控制要求提出制定的.目前国内尚无高温合金、不锈钢真空电子束焊接工艺的统一航标.它的内容与高温合金、不锈钢真空电子束焊接质量检验标准以及一系列国际、国内航空的电子束焊接工艺、质量标准的内容是协调的,目的是一致的.核标准规定了高温合金。不锈钢还空电子束焊接的焊接工艺、焊接设备及接头型式… 相似文献
6.
7.
8.
《无损检测》2018,(11)
对国内外纤维增强树脂基复合材料超声检测标准进行对比分析,有利于吸收国外标准的优点,弥补国内标准的不足,快速提高国内标准的规范性和先进性。分析的标准包括国内的国军标和航标,国外的ASTM(美国材料与试验协会)标准、美军标、波音标准和空客标准等,分析的内容包含标准适用范围、仪器设备质控要求、对比试块、检测参数和检测结果评定等几方面。通过对比分析可以看到:国内应加快相关的纤维增强树脂基复合材料超声检测标准的更新,积极引进先进检测技术,以适应先进设备的使用需求,同时提高标准的实用性;国内标准增加了对比试块制作、信号评定等方面的内容,从而提高了国内检测标准的先进性、准确性和实用性。 相似文献
9.
10.
11.
Crevice corrosion of four kinds of stainless steel, SUS316L, NAS64, NAS185N and NAS254N, in saturated NaCl solution at temperatures up to 100 °C was investigated using the multichannel electrode method. In this method, a pile of five individual working electrodes (WEs) of stainless steel sheet were embedded in epoxy resin and a small hole penetrating through the five WEs was treated as an artificial crevice. Time transition and distribution of the coupling current between the five WEs were measured as a function of crevice depth, kind of stainless steel, temperature and concentration of dissolved oxygen (DO). Anodic or cathodic coupling current on the five WEs of SUS316L changed depending on their corroding state. On the other hand, NAS64, NAS185N and NAS254N showed that the WE outside the crevice contributed as a cathode and that WEs inside the crevice contributed as an anode. The coupling current on SUS316L was strongly affected by concentration of DO, while the coupling current on NAS64, NAS185N and NAS254N was not affected by DO, probably due to the establishment of a passive state inside the crevice. 相似文献
12.
我国熔模精密铸造的历史回顾与发展展望 总被引:1,自引:0,他引:1
概述了熔模精密铸造的特点及在我国的整体发展现状。按照不同产品类别追溯了我国熔模铸造发展的历史、技术进展、行业现状。详细介绍了通用硅溶胶型壳工艺、钛合金熔模铸造工艺、铝合金熔模铸造工艺、石膏型熔模铸造工艺、水玻璃型壳工艺等多种工艺方法以及熔模精密铸造在航空、航天以及一般商用铸件上的应用。指出了我国熔模精密铸造与工业发达国家之间存在的差距,并对我国熔模精密铸造行业的发展提出了几点建议。 相似文献
13.
14.
Owing to their low density and attractive high-temperature properties, gamma titanium aluminide alloys (TiAl alloys, hereafter) have significant potential application in the aerospace and automobile industries, in which these materials may replace the heavier nickel-based superalloys at service temperatures of 600-900℃. Investment casting of TiAl alloys has become the most promising cost-effective technique for the manufacturing of TiAl components. Ceramic moulds are fundamental to fabricating the TiAl casting components. In the present work, ceramic mould with a zirconia primary coat was designed and fabricated successfully. Investment casting of TiAl blades and tensile test of specimens was carried out to verify the correctness and feasibility of the proposed method. The tensile test results indicate that, at room temperature, the tensile strength and the elongation are about 450 MPa and 0.8%, respectively. At 700℃, the tensile strength decreases to about 410 MPa and the elongation increases to 2.7%. Microstructure and mechanical properties of investment cast TiAl alloy are discussed. 相似文献
15.
16.
陈孝国 《稀有金属材料与工程》2007,24(3):29-31
由于国内市场PTA缺口较大,国内各企业掀起一股建设PTA项目的高潮。PTA装置中的钛制容器与其它行业使用的钛制容器相比,在材料、制造、检验等方面有较大的区别,质量要求高,2001年前均采用从国外成套引进。随着国内钛制容器制造水平的不断提高,国产化已成为必然趋势,但国产化也面临一些急需解决的问题。 相似文献
17.
18.
针对我厂与美国合作生产的,当今最为先进的,地面涡轮机组焊接组合件中所选用的典型材料Inco718,410(相当1Cr13)、17-4PH,进行局部消除应力热处理试验。结果表明:用陶瓷型电加热器加热代替炉中整体热处理消除焊接残余应力,方便可行,成本很低。 相似文献