Answer
17-7PH (ASTM A564) wani yanki ne na hazo-austenitic-hardening bakin karfe wanda ke ba da ingantattun kayan aikin injiniya ta hanyar haɗin rage sanyi (Sharadi C) da taurin shekaru masu zuwa (CH900). Ba kamar 302 ko 304 bakin karfe ba, waɗanda ke dogaro da sanyi kawai don aiki don ƙarfi kuma suna rasa fushinsu a yanayin zafi sama da 250 C, 17-7PH CH900 yana kiyaye modulus ɗin sa na roba kuma yana ba da ƙarfi har zuwa 343 C (650 F). Maganin zafi na CH900 ya haɗa da dumama zuwa 482 C (900F) na sa'a ɗaya, wanda ke haifar da mahaɗan tsaka-tsakin aluminium mai wadatar a cikin matrix martensitic. Wannan yana haifar da ƙayyadaddun ƙarancin gajiya da juriya ga annashuwa, yana mai da shi manufa don maɓuɓɓugan ruwan raƙuman ruwa a cikin injinan injin sararin samaniya inda kwanciyar hankali na zafi ya fi muhimmanci.
