Alloy Life Improvement Research Team

Introduction The heat-treating industry is in need of heat-treatment furnace materials and fixtures that have a long service life and reduced heat capacity. Many of the fixtures are consumed within 1 year of exposure in high temperature carburization atmospheres. Most of these fixtures are manufactured using heat resistant alloys. Iron-nickel based and iron-nickel-chromium based alloys are experiencing a variety of degradation mechanisms. Based on microstructural analysis of components that were used until failure in carburization furnace application, it was found that the primary reason for failure was the excessive carburization that leads to “metal dusting” and subsequent cracking. Aluminizing is widely used to increase the high temperature oxidation and carburization resistance of nickel-based alloys.