Abstract
This paper is presenting a new developed high corrosion resistant super-austenitic stainless steel with applications in the chemical process industry. High levels of chromium and molybdenum are resulting in resistance to general forms of corrosion and to localized corrosion in chloride containing media. The pitting resistance equivalent calculated by the weighted sum of chromium, molybdenum and nitrogen is resulting in a pitting resistance equivalent number PREN of 54. A high nickel content supported by alloying with nitrogen offers an improvement in the thermal stability compared to other alloys known of this family. The high nickel content combined with nitrogen is leading to a beneficial low sigma solvus temperature. The low sigma solvus temperature is advantageous in the heat treatment processing of this alloy. Corrosion rates in mineral acids, critical pitting temperature according to ASTM G 48 -Method C and corrosion data from other lab measurements are presented as well as phase calculations for sigma phase formation compared to practical experiences.
