스테인레스강용접 열영향부의 KLA거동 및 기계적 특성에 관한 연구

A study on the KLA behaviors in HAZ and the mechanical properties of austenitic stainless steel weld

  • 조종춘 (한국기계연구소 재료공학연구부) ;
  • 김영석 (조선대학교 공업전문대학) ;
  • 김학민 (한국기계연구소 재료공학연구부)
  • 발행 : 1990.12.01

초록

Integranular corrosion behaviors of KAL (Knife Line Attack) and mechanical properties such as tensile and creep rupture were investigated for the tube material used for nearly 20 years under the condition of 463.deg. C and 28 $kg/cm^2$. Based and weld metal were austenitic stainless steel AISI 321 containing Ti, AISI 347 containing Nb, respectively. KLA is a kind of the intergranular corrosion which often occurs just near the HAZ (heat affected zone) of AISI 321 and AISI 347 stainless steel due to the grain boundary sensitization. In KLA zone, intergranular corrosion crack has propagated outwards from the inner surface and carbides of white and narrow band type assuming as (Cr, Fe) carbide were confirmed. All the delta-ferrite formed in the weld metal during weld solidification has been transformed into sigma-phase since delta-ferrte was exposed for 20 years at 463.deg. C. Elongation was very low at the range from room temperature to 600.deg. C and it was confirmed that creep-rupture properties were not consideralbly affected.

키워드