ELEVATED TEMPERATURE TESRS OF CHROMIUM-TITANIUM-SILICON COATED F48 COLUMBIUM ALLOY BOLT AND NUT

摘要

A F-48 Columbium alloy bolt and nut was submitted to this Laboratory for thermal cycling and metallographic examination. The test bolt and nut was subjected to four 1/2 hour cycles of exposure to 2500F and cooled to room temperature. Prior to, and after each exposure the balt and nut was weighed to .0001 grams and the weight gain determined. following thermal cycling the bolt and nut was cross sectioned and metallographically examined， photographed, and coating thickness measured on the bolt shank and thread areas.