GALVANNEALED HEAT-TREATED STEEL MATERIAL AND PROCESS FOR PRODUCING THE SAME

• Main Authors: ISHII KAZUYA, SHIMADA NAOAKI, KOJIMA NOBUSATO, TOMIZAWA ATSUSHI, NAKAMURA TOYOMITSU, TOKI TAMOTSU, IMAI KAZUHITO
• Format: Patent
• Language: English; Korean
• Published: 19.05.2016
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

자동차용 부재 이용에 알맞는 뛰어난 도장후 내식성 및 고강도를 소유하는 합금화용융아연도금 열처리 강재 및 그 제조 방법을 제공한다. 적어도 한면에 합금화용융아연도금이 행하여진 합금화용융아연도금강재의 적어도 일부를 담금질 가능한 온도영역으로 가열하는 열처리가 행하여진 합금화용융아연도금 열처리 강재이다. 열처리가 행하여진 부분의 적어도 일부의 표면에 잔존하는 피막의 부착량이 한면당 20g/m이상 80g/m이하이며 피막중의 Fe농도가 15% 이상 35% 이하이며 동시에 피막에 η상이 존재하고 또한 피막 표면에서의 중심선 평균 거칠기 정도 Ra가 1.5㎛ 이하이다. A heat treated galvannealed steel material having excellent post-painting corrosion resistance and a high strength which is suitable for use as an automotive part and a method for its manufacture are provided. A galvannealed steel material having a galvannealed coating on at least one side thereof is heat treated by heating at least a portion thereof to a temperature range in which hardening is possible. The coating remaining on the surface of at least a part of the portion which underwent heat treatment has a coating weight of at least 20 g/m 2 and at most 80 g/m 2 per side and an Fe content of at least 15% and at most 35%, an · phase is present in the coating, and the centerline average roughness Ra of the surface of the coating is at most 1.5 µm.