Corodur Coroloy CO description: COROLOY Co is a high alloyed Cr- Mo- Co- W- flux cored Nickel based wire. This alloy is suitable for steel that encounters aggressive corrosive media as well as those steels that operate at high temperatures. This hardfacing alloy is extraordinarily resistant on impact, pressure loads and high temperature environments, which results in hardening of the deposit up to a hardness of about 420 HB with little deformation. When build-up layers are required, CORODUR 200 K is recommended as a buffer layer. It is also recommended that the base material should be preheated to about 300C – 400C before hardfacing. For multi layer welding low interpass temperature and low energy input is recommended.