내용접 고온 균열성이 우수한 고Ni 합금

• Main Authors: NISHIDA YUKIHIRO, OSUKI TAKAHIRO, TSUGE SHINJI
• Format: Patent
• Language: Korean
• Published: 19.05.2023
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

질량％로, Cr: 16 내지 30％, Ni: 18 내지 50％, Al: 0.01 내지 1.0％, Ti: 0.01 내지 1.5％를 함유하는 내용접 고온 균열성이 우수한 고Ni 합금이다.　제1 발명은, 원 상당 직경 1.0㎛ 이상의 TiC계 석출물의 개수 밀도와 강 중 Mg 함유량의 관계가 이하의 (1) 식을 만족시킨다.　제2 발명은, 산화물계 개재물 및 황화물계 개재물 중의 S의 평균 농도가 질량％로 0.70％ 이상이다.　제3 발명은, O 또는 S가 검출된 개재물의 평균 Ca, Mg, Al 농도로부터 산출한 개재물 중 CaO, MgO 및 Al2O3의 질량비가 식 (2)를 만족시킨다.　TiC의 개수 밀도(개/mm2)≤463-9.5×강 중 Mg 농도(질량ppm) ... (1) [CaO-0.6×MgO](질량％)/[CaO+MgO+Al2O3](질량％)≥0.20 ... (2) A high-Ni alloy having excellent weld-hot-cracking resistance includes, in mass%, Cr: 16-30%, Ni: 18-50%, Al: 0.01-1.0%, and Ti: 0.01-1.5%. In a first aspect of the invention, a relationship between number density of TiC precipitates having 1.0 µm or more of equivalent circle diameter and Mg content in steel satisfies formula (1) below. In a second aspect of the invention, S average concentration in oxide- and sulfide- inclusions is 0.70 mass% or more. In a third aspect of the invention, mass ratios of CaO, MgO, and Al2O3 in inclusions, where O or S is detected, satisfy formula (2), the mass ratios being respectively calculated from average concentrations of Ca, Mg and Al in the inclusions, (1) number density of TiC (number of pieces/mm2) ≤ 463 - 9.5 × Mg concentration in steel (mass ppm) and (2) [CaO - 0.6 × MgO] (mass%)/[CaO + MgO + Al2O3] (mass%) ≥ 0.20.