According to EN545 standard, ductile iron castings must adhere to strict sampling and test bar preparation specifications during tensile testing to ensure accurate assessment of material properties. The following is an overview of key requirements:
I. Sampling Requirements
The thickness of the specimen and the diameter of the test bar must conform to the specifications in Table 14 of the standard.
1. Centrifugally Cast Pipes A sample should be cut from the DINSEN ductile iron pipe spigot. The sampling direction can be parallel or perpendicular to the pipe axis. In case of dispute, the sampling result parallel to the axis shall prevail.
2. Non-Centrifugally Cast Pipes, Fittings, and Accessories The manufacturer may choose to cast the specimen integrally with the casting or cast it separately. If cast separately, the specimen must be cast using metal from the same batch as the casting. If the casting requires heat treatment, the specimen should also undergo the same process simultaneously.
II. Bar Preparation Specifications
One tensile test bar should be fabricated for each sample. This test bar must represent the material properties of the middle thickness region of the sample, and its cylindrical section diameter should conform to the specifications in Table 14.
- Gazelle length: Should not be less than 5 times the nominal diameter of the test bar.
- End design: Must be compatible with the clamping system of the testing machine used.
- Surface roughness: The surface roughness Rz value of the cylindrical section must not exceed 6.3 μm.
If the test bar diameter specified in Table 14 exceeds 60% of the measured minimum thickness of the sample, the following adjustments are permitted:
- Fabricate a test bar with a smaller diameter;
- Or recut the sample from a section of the tube with greater thickness.
Post time: Nov-10-2025
