Process for removal of chloride ions from steel surfaces
US6425997B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Jun 20, 2000 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Jun 20, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25F1/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A process for removing chloride ions from steel surfaces and measuring the amount present on the steel surface being tested employs a high frequency waveform alternating current treatment as a pre-measurement step to liberate the chloride ions into deionized water on the steel surface being tested. The conductivity of the water containing the chloride ions is measured in a conductivity cell mounted on the same steel surface being tested. Recovery of chloride ions originally present on the steel test surface (cathode) is 85-95% complete when a sine wave high frequency alternating current is used between the steel test surface (cathode) sealed below an insulating plastic box containing the deionized water and which plastic box contains a steel plate (anode) mounted within and immediately below the inside top of the plastic box conductivity cell. The conductivity of the water in the cell is measured by a conductivity meter after disconnecting the high frequency waveform alternating current. The conductivity of the water in the cell after pretreatment is converted to &mgr;g of chloride ions per sq. cm. A field instrument to measure chloride ions per sq. cm. can be built utilizing such …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.