Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


한국표면공학회지 (28권5호 300-308)

Study of Characteristics of Hot Dip Galvanized Steel Strip by Oxygen-free Finishing

비산화성 분위기에 의한 용융아연도금의 특성 연구


포항제철(주) 기술연구소 광양압연연구팀;산업과학기술연구소 표면처리연구팀;
포항제철(주) 기술연구소 광양압연연구팀;산업과학기술연구소 표면처리연구팀;


The effect of nitrogen finishing for the control of coating weight in a nitrogen sealing box on the coating surface property in hot dip galvanizing process has been studied. The coated surface is free of oxide marks and edge overcoated. The coating uniformity is excellent ; the standard deviation of the coating thickness along width of the specimen was $1~1.2mu extrm{m}$ in the box whereas $2.5~3mu extrm{m}$ in the air. Considering surface quality of the coating such as oxide mark, edge overcoated and zinc dust, the oxygen content between 40 and 200 ppm was suggested in the box in addition the oxygen content of at least 40 ppm or the minimum dew point of $-27^{circ}C$ is required to prevent a zinc vaporization.