Wie prüft man die Qualität von verzinktem Stahl?

To quickly assess galvanized steel quality, check the coating thickness, adhesion, surface condition, and dimensions. Look for defects like rust or cracks. Use a gauge to measure the zinc coating, perform a scratch or bend adhesion test, and verify the steel’s dimensions and surface uniformity. These quick checks ensure the steel meets quality standards.

For more detail, this guide covers the methods for checking the quality of galvanized steel and the standards to follow. It will help you ensure that you receive a compliant, high-quality product.

Overview of Galvanized Steel Inspection Methods

This table introduces the most commonly used testing techniques that assess various critical aspects of galvanized steel, from dimensional accuracy to coating integrity. By following these, you can effectively determine whether the steel meets industry standards and is suitable for its intended applications.

Visuelle Inspektion

Visual inspection is a crucial first step in evaluating galvanized steel, as it provides immediate insight into the surface quality and overall integrity of the coating.

What to Check

• Look for visible defects such as rust, discoloration, scratches, or uneven coating.
• Check for spangles (the crystalline pattern on the surface) if uniformity is important for aesthetics.
• Ensure the surface is free from blisters, cracks, or peeling.

Dimensional Check

Dimensional inspection involves verifying the key physical measurements of galvanized steel, such as thickness, width, and length, to ensure they meet specified tolerances. This is the most fundamental test.

The accuracy of these dimensions is influenced by factors such as the steel’s manufacturing process, the precision of the measurement tools used, and the consistency of the galvanizing process. Ensuring precise dimensions is critical for the steel’s suitability in its intended application.

Coating Thickness Check

Coating thickness is a critical factor in ensuring the durability and corrosion resistance of galvanized steel. Accurate measurement of the zinc layer is essential to confirm it meets the required standards for performance and protection.

Methods Used

• Magnetic Gauge: Measures the thickness of the zinc coating by detecting changes in magnetic flux, ideal for non-destructive testing.
• Eddy Current Gauge: Uses electromagnetic fields to measure coating thickness, often used for more precise readings on thin coatings.

These methods are both quick and reliable, providing essential data for ensuring adequate corrosion protection.

Adhesion of Coating Check

The adhesion of the galvanized coating to the steel substrate is vital for long-term performance, as a strong bond ensures the coating remains intact under mechanical stress and environmental exposure.

Methods Used

• Cross-Hatch Test: Involves making a grid of cuts on the coating and using tape to check if the coating is easily removed, indicating poor adhesion.
• Biegetest: The steel is bent to a specified angle, and if the coating cracks or peels, it suggests weak adhesion.
• Peel Test (Destructive): A small section of the coating is peeled off to directly assess the strength of the bond between the zinc and the steel.

These tests are essential for verifying that the coating will not fail under normal use conditions.

Corrosion Resistance Check

Corrosion resistance is a key indicator of galvanized steel’s long-term durability, ensuring it can withstand harsh environments without deteriorating.

Salt Spray Test (Neutral Salt Spray, NSS)

Exposes the steel to a controlled saline mist to accelerate corrosion, simulating the effects of prolonged exposure to moisture and salt, and evaluating the coating’s ability to protect the substrate. This method provides a clear measure of the steel’s resistance to rust and corrosion under extreme conditions.

Härteprüfung

The hardness of galvanized steel is critical for assessing its resistance to wear, deformation, and impact, which directly affects its suitability for demanding applications.

Methods Used

• Rockwell-Härteprüfung

Measures the depth of penetration of a diamond or steel ball under a specific load, providing a quick and reliable indication of the material’s hardness.

• Vickers-Härteprüfung

This involves applying a precise load to a diamond indenter and measuring the size of the indentation, offering a more detailed and accurate assessment, especially for thin coatings or small areas. Both tests help determine the steel’s mechanical properties and its ability to withstand physical stress.

Cross-Sectional Examination

Cross-sectional examination provides an in-depth analysis of the galvanized coating’s structure and its bond to the steel, ensuring the coating’s uniformity, integrity, and proper formation.

Microscopic Examination

Involves cutting and polishing a sample to reveal the zinc coating and its interface with the steel substrate. This allows for detailed observation of coating thickness, layer structure, and adhesion, helping to detect any internal defects like voids, cracks, or incomplete coverage.

This method is essential for confirming the quality of the galvanizing process at a microscopic level.

Premium Galvanized Steel You Can Rely On

When it comes to galvanized steel, Steel Pro Group is the trusted name for quality that lasts. We take pride in our meticulous quality control process, ensuring every sheet of steel meets strict standards for coating thickness, surface quality, and dimensional precision.

Choose us for galvanized steel that works as hard as you do. Your projects deserve the best products, and with Steel Pro Group, that’s exactly what you get.