Form This specification covers a corrosion and heat-resistant steel in the form of investment castings. Application These castings have been used typically for parts requiring corrosion and heat resistance up to 800 ??(427 ?? especially when such parts are welded during fabrication@ for parts requiring oxidation resistance up to 1500 ??(816 ?? but useful at that temperature only when stresses are low@ and for parts requiring resistance to fuming nitric acid@ but usage is not limited to such applications.