Steel bar for downhole member, and downhole member
US10995394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 2017 |
| Grant date | May 4, 2021 |
| Priority date | — |
| Expiry date | Aug 8, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel bar for a downhole member is provided that is excellent in SCC resistance and SSC resistance. A martensitic stainless steel bar material for a downhole member of the present embodiment has a chemical composition that contains, by mass %, C: 0.020% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.03% or less, S: 0.01% or less, Cu: 0.10 to 2.50%, Cr: 10 to 14%, Ni: 1.5 to 7.0%, Mo: 0.2 to 3.0%, Ti: 0.05 to 0.3%, V: 0.01 to 0.10%, Nb: 0.1% or less, Al: 0.001 to 0.1% and N: 0.05% or less, with the balance being Fe and impurities, and satisfies Formula (1) and Formula (2). [Mo]−4×[total Mo amount in precipitate at R/2 position]≥1.30 (1)[Total Mo amount in precipitate at center position]−[total Mo amount in precipitate at R/2 position]≤0.03 (2)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.