ASME Section II Materials is in the process of adding a supplementary requirement to adopted ASTM specifications prescribing a minimum cooling rate after austenitizing Grade 91 Type 2 products. The specific wording which has been approved by Section II for the new supplementary requirement is as follows: "For Grade FP91 Type 2 material, the heat treatment shall ensure that following austenitizing the rate of cooling from 1,650°F to 900 °F (900°C to 480 °C) is no slower than 9 °F/min (5 °C/ min)."
Date Initiated: 09-18-2022
Technical Contact: Keith Hottle
Item: 000
Ballot:
Status: