| 摘要 |
<p>1,154,222. Cast iron. REGIE NATIONALE DES USINES RENAULT July 4,1966 [July 27, 1965No. 29901/66. Heading C7A. Cast-iron parts having a high coefficient of thermal expansion are made of an alloy comprising:- wherein the Al may partially replace the si with a minimum for the latter of 0À5% the balance, apart from impurities, being iron and are austenetized at 825-1100‹C. after casting, isothermally treated at 350-450‹ C. (e.g. in a molten salt or metal bath or in a fluidized bed) during cooling for a sufficient time such that some stable austenite subsist upon cooling in air, oil or water (e.g. 15-70% austenite). The body may then be tempered (e.g. at 360‹ C.) or may be subjected to local treatment by austenetization and quenching or by cold rolling. The alloy so treated is described as useful for wetjackets for I.C. engines with aluminium crankcases.</p> |
