René 41

René 41 is an age hardening nickel base superalloy with exceptional strength from room temperature through about 1600°F. The alloy is sensitive to strain age cracking during welding. Sound welds can be made by the resistance and electron beam methods. GTAW using DC straight polarity requires good joint fit-up and cooling by means of copper backup bars or water-cooled fixtures. René 41 should be in the fully solution treated condition prior to welding. After welding the assembly should be solution treated using rapid heating and cooling rates through the 1200-1600°F range, followed by aging.

Mechanical properties vary with the solution and aging treatments. Higher solution temperatures result in better room temperature ductility and elevated temperature creep-rupture strength. Lower solution temperatures give higher tensile strengths. Two commonly used heat treatments are:

1. Solution treat: 2150°F 4 hours, air cool. Age: Reheat 1650 °F 4 hours, air cool.
2. Solution treat: 1975 °F 4 hours, air cool. Age: Reheat 1400°F 16 hours, air cool.