Method for determining the corrosion resistance of deep-drawable iron sheets for body parts of motor vehicles and apparatus for performing the method

US4985622A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Rudolf Kessler · Reutlingen, DE
• Winfried Degen · Eßlingen, DE
• Dieter Oelkrug · Tübingen, DE
• Martin Tubach · Reutlingen, DE

Key dates

• Filing date: Jun 12, 1989
• Grant date: Jan 15, 1991
• Expiry date: Jun 12, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/3137
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and an apparatus determines a predicted corrosion resistance of deep-drawable iron sheets for body parts of motor vehicles. The method is caarried out with a measuring apparatus comprising one or more light sources with which the iron sheet is irradiated. The reflected light is concentrated by lenses, filtered through filters and the filtered light rays are imaged on a plurality of photoreceivers. The ratios of two respective filter wavelengths are evaluated by a computer from the signals thus obtained. From the values of the quotients of the filter wavelengths, predictions can then be made as to the paint migration values to be expected of the deep-drawable iron sheets painted in a later operation. A simple quality control of the iron sheets supplied by manufacturers for the production of components for motor vehicles can be based on these values.