HVOF용사 코팅한 SM490B용접재의 피로크랙성장에 미치는 후 열처리의 영향

다국어 초록 (Multilingual Abstract)

High velocity oxygen-fuel thermal spray coating of the WC-Co cermet material is a well-established process for modifying the surface properties of the structural components exposed to the corrosive and wear attacks. In this study, HVOF coated SM490B are prepared to evaluation of the effect of coating and post-heat treatment on fatigue crack growth behavior. The pre-crack of the fatigue crack growth test specimens machined at deposited material area, heat affected zone and boundary, respectively. Through these test, the following results are obtained: 1) The fatigue crack of coated specimens propagated more rapidly than non-coated specimen in all specimens. 2) In the same coating thickness specimens, the specimens with pre-crack at boundary more rapidly propagated than the specimens with pre-crack at HAZ and deposited material area. This is probably because whereas the structure of the deposited material zone is very strong thanks to evenly distributed minute carbide or minute martensite, the structure of the edge is highly unstable and contains diverse defects. 3) In three type specimens, the fatigue crack growth rate of post-heat treatment specimen decrease in near-threshold value, while it was about the same in intermediated region and high growth rate region. These results can be used as basic data in a structural integrity evaluation of rolled SM490B weldments considering HVOF coating.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 실험방법
• 3. 피로균열 진전시험 및 결과 고찰
• 4. 결론
• References