초고속 용사 적용 고속 초고압 왕복동 펌프 플런저의 내구성 특성에 관한 연구 (A Study on Characteristics of Durability for Plunger of High Speed and Ultra-High Pressure Reciprocating Pump Using High Velocity Oxygen Fuel Spraying)

서지정보

· 발행기관 : 한국자동차공학회
· 수록지 정보 : 한국자동차공학회 논문집 / 22권 / 5호 / 20 ~ 28페이지
· 저자명 : 배명환, 박병호, 정화, 박희성

초록

The high velocity oxygen fuel spraying (HVOF) is a kind of surface modification process technology toform the sprayed coating layer after spraying the powder to molten or semi-molten state by the ultra-high speed at thehigh-temperature heat source and conflicting with a substrate. It is desirable to melt completely the thermal spraypowder in order to produce the coating layer with an optimal adhesion, however, because a semi-molten powder in aspray process has the low efficiency and become a factor that degrades the mechanical property by the inducement ofpore-forming within the coating layer. To improve the wear resistance, corrosion resistance and heat resistance, in thisstudy, the plungers of high-speed and ultra-high pressure reciprocating hydraulic pumps for oil and water used inironwork are produced with 420J2 and the coating layers of plungers are formed by the powders of WC-Co-Cr andWC-Cr-Ni including the high hardness WC. The surface of these plungers is modified by the super-mirror face grindingmachine using variable air pressure developed in this laboratory, and then the characteristics of cross-sectionalmicrostructure, and surface roughness and hardness values between no operation and 100 days-operation are examinedand made a comparison. The fine tops and bottoms on surface roughness curve of oil-hydraulic pump plunger sprayedby WC-Cr-Ni are molded more and higher than those of water-hydraulic pump sprayed by WC-Co-Cr because theplunger diameter of oil-hydraulic pump is 0.4 times smaller than that of water-hydraulic pump and the pressure of oilhydraulicpump exerted on the plunger is operated with the 70 bars higher than that of water-hydraulic pump. As aresult, it is found that the values of centerline average surface roughness and maximum height for oil-hydraulic pumpplunger are bigger than those of water-hydraulic pump plunger.

영어초록

The high velocity oxygen fuel spraying (HVOF) is a kind of surface modification process technology toform the sprayed coating layer after spraying the powder to molten or semi-molten state by the ultra-high speed at thehigh-temperature heat source and conflicting with a substrate. It is desirable to melt completely the thermal spraypowder in order to produce the coating layer with an optimal adhesion, however, because a semi-molten powder in aspray process has the low efficiency and become a factor that degrades the mechanical property by the inducement ofpore-forming within the coating layer. To improve the wear resistance, corrosion resistance and heat resistance, in thisstudy, the plungers of high-speed and ultra-high pressure reciprocating hydraulic pumps for oil and water used inironwork are produced with 420J2 and the coating layers of plungers are formed by the powders of WC-Co-Cr andWC-Cr-Ni including the high hardness WC. The surface of these plungers is modified by the super-mirror face grindingmachine using variable air pressure developed in this laboratory, and then the characteristics of cross-sectionalmicrostructure, and surface roughness and hardness values between no operation and 100 days-operation are examinedand made a comparison. The fine tops and bottoms on surface roughness curve of oil-hydraulic pump plunger sprayedby WC-Cr-Ni are molded more and higher than those of water-hydraulic pump sprayed by WC-Co-Cr because theplunger diameter of oil-hydraulic pump is 0.4 times smaller than that of water-hydraulic pump and the pressure of oilhydraulicpump exerted on the plunger is operated with the 70 bars higher than that of water-hydraulic pump. As aresult, it is found that the values of centerline average surface roughness and maximum height for oil-hydraulic pumpplunger are bigger than those of water-hydraulic pump plunger.

참고자료

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