| 摘要 |
A clad steel pipe excellent in corrosion resistance and low-temperature toughness, which comprises a cladding sheet of high corrosion resistant steel and a substrate sheet of low-alloy high-strength steel, the substrate sheet consisting, as the fundamental constituents, essentially of: carbon: from 0.002 to 0.050 wt. %, silicon: from 0.05 to 0.80 wt. %, manganese: from 0.80 to 2.20 wt. %, niobium: from 0.01 to 0.10 wt. %, aluminum: from 0.01 to 0.08 wt. %, nitrogen: from 0.002 to 0.008 wt. %, and, the balance being iron and incidental impurities; or, the substrate sheet further additionally containing, as the strength-improving constituents, at least one element selected from the group consisting of: copper: from 0.05 to 1.00 wt. %, nickel: from 0.05 to 3.00 wt. %, chromium: from 0.05 to 1.00 wt. %, molybdenum: from 0.03 to 0.80 wt. %, vanadium: from 0.01 to 0.10 wt. %, and, boron: from 0.0003 to 0.0030 wt. %; or, the substrate sheet further additionally containing, as the toughness-improving constituent, titanium within the range of from 0.005 to 0.030 wt. %, the clad steel pipe being subjected to a solution treatment under the following conditions: heating temperature: from 900 DEG to 1,150 DEG C., holding period: up to 15 minutes, and, cooling rate: from 5 DEG to 100 DEG C./second. |
