PURPOSE: To obtain Zr or Zr alloy having satisfactory corrosion resistance by subjecting the Zr or Zr alloy to a surface treatment using an oxidizing acid contg. oxidizing metallic ion thereby forming easily a protective film on the surface.
CONSTITUTION: Zr or Zr alloy is subjected to a surface treatment by an oxidizing acid contg. ≥1 kinds of oxidizing metallic ions such as Ru ion, Rh ion, Pd ion, etc. Mixed acids composed of 1 or ≥2 kinds among HNO3, H2O2, HClO, etc. are used as the above-mentioned acid. The preferable treating conditions are: The concn. of nitric acid is 14mol/l (65%) which is approximately the azerotropic concn., the concn. of the Ru ion is 1×10-3mol/l and the treating temp. is the boiling temp. (120°C). The uniform protective film is easily formed on the surface of the Zr or Zr alloy by such surface treatment by which the corrosion resistance is considerably improved.
SUZUKI KATSUMI
MINATO AKIRA
YOSHIDA TOMIO
| JPS5839785A | 1983-03-08 | |||
| JPS56166378A | 1981-12-21 |
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