Techalloy 2209 description: Techalloy 2209 is a filler metal designed to weld 22% chromium duplex stainless steels such as UNS S31803 and S32205. The weld metal poses a high tensile and yield strength. This grade has very good resistance to stress corrosion cracking and pitting corrosion with typical pitting resistance equivalent number (PREN) of 35-36.