High alloy for oil well
View Patent ↗The high alloy for oil well according to the present embodiment consists of, in mass %, C: 0.03% or less, Si: 1.0% or less, Mn: 0.05 to 1.5%, P: 0.03% or less, S: 0.03% or less, Ni: 26.0 to 40.0%, Cr: 22.0 to 30.0%, Mo: 0.01% or more to less than 5.0%, Cu: 0.1 to 3.0%, Al: 0.001 to 0.30%, N: more than 0.05% to 0.30% or less, O: 0.010% or less, and Ag: 0.005 to 1.0%, wherein the alloy satisfies the following Formula (1) and (2), wherein the high alloy for oil well has yield strength of 758 MPa or more: 5×Cu+(1000×Ag) 2 ≥40 (1) Cu+6×Ag−500×(Ca+Mg+REM)≤3.5 (2) where, each element symbol in each Formula is substituted by the content (in mass %) of each element.
1. A high alloy for oil well having a chemical composition which consists of, in mass %,
C: 0.03% or less,
Si: 1.0% or less,
Mn: 0.05 to 1.5%,
P: 0.03% or less,
S: 0.03% or less,
Ni: 26.0 to 40.0%,
Cr: 22.0 to 30.0%,
Mo: 0.01% or more to less than 5.0%,
Cu: 0.1 to 2.5%,
Al: 0.001 to 0.30%,
N: more than 0.05% to 0.30% or less,
O: 0.010% or less,
Ag: 0.005 to 1.0%,
Ca: 0 to 0.01%,
Mg: 0 to 0.01%, and
rare earth metals: 0 to 0.2%, with the balance being Fe and impurities, and satisfies the following Formulae (1) and (2), wherein
the high alloy for oil well has yield strength of 758 MPa or more:
5×Cu−(1000×Ag) 2 ≥40 (1)
Cu+6×Ag−500×(Ca+Mg+REM)≤3.5 (2)
where, each element symbol in Formulae (1) and (2) is substituted by the content in mass % of each element, and REM is substituted by a total content in mass % of the rare earth metals.
2. The high alloy for oil well according to claim 1 ,
wherein a content of Ca is: 0.0005 to 0.01 mass %.
3. The high alloy for oil well according to claim 1 , wherein a content of Mg is: 0.0005 to 0.01 mass %.
4. The high alloy for oil well according to claim 1 , wherein a content of rare earth metals is: 0.001 to 0.2 mass %.