9Cr-W-Mo-V-Nb鋼の高温引張特性及び靭性に及ぼす熱処理の影響

Effect of heat treatment on high temperature tensile property and toughness in 9Cr-W-Mo-V-Nb steel

小原 智史; 山田 芳之*; 中澤 崇徳*

Obara, Satoshi; Yamada, Yoshiyuki*; Nakazawa, Takanori*

焼ならし及び焼戻し熱処理条件を広範囲に変化させたW含有高クロムフェライト系耐熱鋼において、高温引張特性と靭性に及ぼす熱処理の影響について評価を行った。引張強度は、焼ならし温度の上昇とともに増加し、焼戻し時間及び時間の増加により低下する。シャルピー衝撃試験においては、焼ならし温度の上昇とともに延性脆性破面遷移温度が上昇し、上部棚吸収エネルギーは低下した。一方、焼戻し温度の上昇や時間の増加とともに遷移温度は低下し、吸収エネルギーは増加した。

This presentation shows the effect of heat treatment on high tensile property and toughness in W added high Cr ferritic heat resistant steel with several heat treatments. In the tensile test at evaluated temperature, the tensile strength was increased with increasing normalizing temperature. On the contrary, the tensile strength was decreased with increasing tempering temperature and time. In the Charpy impact test, fracture appearance transition temperature (FATT) was increased and upper shelf energy (USE) was decreased with increasing normalizing temperature. On the contrary, the FATT was decreased and USE was increased with increasing tempering temperature and time.