AUSTENITIC STAINLESS STEEL AND MANUFACTURING METHOD THEREOF

• Main Authors: KIM, Sangseok, PARK, Mi-nam
• Format: Patent
• Language: English; French; Korean
• Published: 10.03.2022
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present specification relates to austenitic stainless steel which can be utilized as various materials for an outer panel of a vehicle, a component for construction and the like, and a manufacturing method thereof. According to an embodiment, the austenitic stainless steel comprises, by weight %, 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 9% of Ni, 16 to 19% of Cr, 0.2% or less of N, and the remainder being Fe and unavoidable impurities. When the total thickness of the steel material is t, the value of an average grain size d in the thickness of 1/4t to 3/4t is 5㎛ or less, the value of ASP expressed by formula (1) below is 10 to 25, the value of formula (2) below is 435 or higher, and the value of formula (3) below can be 6000 or higher. (1) 551 - 462*([C]+[N]) - 9.2*[Si] - 8.1*[Mn] - 13.7*[Cr] - 29*([Ni]+[Cu])-18.5*[Mo] - 68*([Nb]+[V]) (2) (1600*[N]) + (700/√α)+ (4*ASP) - (20*[Ni]) + 100 (3) YS*EL - 500*([Ni]+[Cr]) In formulas (1), (2) and (3), [C], [N], [Si], [Mn], [Cr], [Ni], [Cu], [Mo], [Nb] and [V] represent the weight percentages of respective elements, YS represents yield strength (MPa), and EL represents elongation (%). La présente invention concerne un acier inoxydable austénitique qui peut être utilisé en tant que matériaux divers pour un panneau externe d'un véhicule, un composant pour la construction et similaire, et son procédé de fabrication. Selon un mode de réalisation, l'acier inoxydable austénitique comprend, en poids, 0 005 à 0,03 % de C, 0,1 à 1 % de Si, 0,1 à 2 % de Mn, 6 à 9 % de Ni, 16 à 19 % de Cr, 0,2 % ou moins de N, et le reste étant Du Fe et des impuretés inévitables. Lorsque l'épaisseur totale du matériau en acier est t, la valeur d'une taille de grain moyenne d dans l'épaisseur de 1/4t à 3/4t est de 5 µm ou moins, la valeur de ASP exprimée par la formule (1) ci-dessous est de 10 à 25, la valeur de formule (2) ci-dessous est de 435 ou plus, et la valeur de formule (3) ci-dessous peut être de 6000 ou plus. (1) 551-462 * ( [C] + [N])-9,2 * [Si]-8,1 * [Mn]-13,7 * [Cr]-29 * ( [Ni] + [Cu]) 18,5 * [Mo]-68 * ( [Nb] + [V]) (2) (1600 * [N]) + (700/√ alpha) + (4 * ASP))- (20 * [Ni]) + 100 (3) YS * EL-500 * ( [Ni] + [Cr]) Dans les formules (1), (2) et (3), [C], [N], [Si], [Mn], [Cr], [Ni], [Cu], [Mo], [Nb] et [V] représentent les pourcentages en poids des Éléments respectifs, YS représente La limite d'élasticité (MPa), et EL représente un allongement (%). 본 명세서에서는 자동차 외판용, 건축용 부품용 등 다양한 소재로 활용이 가능한 오스테나이트계 스테인리스강 및 그 제조방법에 관한 것이다. 개시되는 오스테나이트계 스테인리스강의 일 실시예에 따르면 중량%로, C: 0.005 내지 0.03%, Si: 0.1 내지 1%, Mn: 0.1 내지 2%, Ni: 6 내지 9%, Cr: 16 내지 19%, N: 0.2% 이하, 나머지 Fe 및 불가피한 불순물을 포함하고, 강재 전체 두께를 t라고 할 때 두께 1/4t~3/4t에서 평균 결정립 크기 d값이 5㎛ 이하이며, 하기 식 (1)로 표현되는 ASP 값이 10 내지 25이고, 하기 식 (2) 값이 435 이상이며, 하기 식 (3) 값이 6000 이상일 수 있다. (1) 551 - 462*([C]+[N]) - 9.2*[Si] - 8.1*[Mn] - 13.7*[Cr] - 29*([Ni]+[Cu])-18.5*[Mo] - 68*([Nb]+[V]) (2) (1600*[N]) + (700/√α)+ (4*ASP) - (20*[Ni]) + 100 (3) YS*EL - 500*([Ni]+[Cr]) 상기 식 (1), (2), (3)에서, [C], [N], [Si], [Mn], [Cr], [Ni], [Cu], [Mo], [Nb], [V]는 각 원소의 중량%를, YS는 항복강도(MPa), EL은 연신율(%)을 의미한다.