Abstract

Measurements and data are reported for the total hemispherical emissivity of Grade 91 steel [ASTM International (ASTM) A387 Grade 91] for the temperature range of 400 K to 1048 K using ASTM standard C835-06. The surfaces studied included (1) an electric discharge machining (EDM) cut, (2) Grade 91 steel sandblasted with 320-grit-sized alumina beads, (3) EDM-cut Grade 91 steel oxidized in air, and (4) Grade 91 steel sandblasted with 320-grit-sized alumina beads and oxidized in air. The EDM-cut Grade 91 steel was oxidized at 873 K and 1023 K for 1, 3, and 5 h. The 320-grit sandblasted Grade 91 steel was oxidized at 1023 K for 5 h. Air oxidations were carried out in a three-zone furnace at fixed airflow. It appears that under some conditions, Grade 91 steel can reach the emissivities required for passive heat removal during an air ingress accident.

摘要

使用 ASTM 标准 C835-06 在 400 K 至 1048 K 的温度范围内报告了 91 级钢 [ASTM 国际 (ASTM) A387 91 级] 的总半球发射率的测量值和数据。研究的表面包括 (1) 电火花加工 (EDM) 切割，(2) 用 320 粒度氧化铝珠喷砂的 91 级钢，(3) 在空气中氧化的 EDM 切割的 91 级钢，以及 (4) 级91 钢用 320 粒度的氧化铝珠喷砂并在空气中氧化。EDM 切割的 91 级钢在 873 K 和 1023 K 下氧化 1、3 和 5 小时。320 粒度喷砂的 91 级钢在 1023 K 下氧化 5 小时。空气氧化在三区炉中以固定气流进行。在某些条件下，91 级钢似乎可以达到在空气进入事故期间被动散热所需的发射率。