高纯金属铬:燃气涡轮机专用高温合金的供应问题
high-purity chromium metal: supply issues forgas-turbine superalloys
根据 1995 年美国科学院(us academy of sciences)的一份报告,《高纯金属铬:燃气涡轮机专用高温合金的供应问题》第二页第三段【共计 74 页之第 16 页,page 2 (16 of 74)paragraph 3】摘译如下:
历史上,电解金属铬用于要求纯度高的航空航天高温合金,而铝热金属铬用于允许纯度较低的一些高温合金。然而,过去十年,高档铝热金属铬的质量有所改进,航空航天发动机制造商已认证这一高档铝热金属铬用于某些较高档的高温合金。尽管现在可以使用一些与电解金属铬质量相当的铝热金属铬材料,但改用铝热金属铬生产叶片等关键部件时必须经过生产厂家和用户双方同意才行,而且必须经过广泛而全面的资格认定研究才行,这种资格认定研究将涉及到合金的生产和测试、试样及铸造和锻造成品的生产和检测、以及可能含有铝热金属铬发动机的生产与测试。类似的限制都要和任何工艺改变联系起来。
"historically, electrolytic chromium metal was used for those aerospace superalloys that required high-purity specifications, and aluminothermic chromium metal was used for those superalloys that allowed lower-purity applications. the quality of high-grade aluminothermic chromium metal has improved over the past decade, however, and aerospace engine manufacturers have certified this material for some higher-grade superalloys. while aluminothermic material of equivalent quality to the electrolytic material may now be available, changes in such critical applications as rotor-grade materials must be mutually acceptable to producer and user and will have to be subject to extensive qualification studies involving production and testing of alloys, test specimens, final cast and forged products, and possibly engines containing them. similar constraints are associated with any process changes."
以上仅为美国科学院报告的一部分,因此,是很有价值的。
高温合金中铬可使喷气发动机在高温、高应力、氧化环境中运转。