원전 증기 터빈재료의 화염경화공정에 따른 액적충격침식특성

다국어 초록 (Multilingual Abstract)

To improve liquid impact erosion resistance by strengthening 'the surface of 12Cr steel(l2Cr, 0,3Mn, 01.C, bal. Fe) which is currently used as steam turbine blade material, flame hardening method which is simple process, without having interface, possible to apply to large surface area has been studied to find its optimal condition as a function of flame temperature and cooling conditions. Erosion test is conducted for flame hardened material with maximum water jet speed of about 600m/s by using liquid impact erosion tester. Erosion resistance is analysed by optical and scanning electron microscopes to measure the depth of eroded specimens and its decreased mass. Degree of the surface hardened 12Cr steel was not observed below specimen's surface temperature of 900℃, whereas hardening is observed by martensite transformation above 1,000℃ in austenite region. The surface hardness in hardened layer of 12Cr steel is about two times higher than that of as-received specimen(300KHN). This phenomena would be due to the non-uniformed strain and the increasing of carbon solid solution in the specimen. The result of X-ray diffraction pattern analysis showed that peak-broadening and lattice expansion is occurred with increasing of flame hardening temperature.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 실험방법
• 3. 실험결과 및 고찰
• 4. 결론
• 후기
• 참고문헌