The bend test is a simple and inexpensive qualitative test that can be used to evaluate both the ductility and soundness of a material. It is often used as a quality control test for butt-welded joints, having the advantage of simplicity of both test piece and equipment.
The bend test may be free formed or guided.
The guided bend test is where the coupon is wrapped around a former of a specified diameter and is the type of test specified in the welding procedure and welder qualification specifications. For example, it may be a requirement in ASME IX, ISO 9606 and ISO 15614 Part 1, API 1104, AWS D1.1
But how to apply the Test preparation correctly is depending on specified code that are being used in the project. It’s may confused and take times for review and perusal.
There’re three factors determine the bend radius to be used. These are:
- the code or standard, the type of bend test ( Face, Root, Side )
- the material mechanical property that being welded, and
- the thickness.
Each code and standard lists the required bend radius and the associated roller spacing to be used for a given material and thickness. The following paragraph references are from several popular codes and standards:
|Code or Standard||Bend Radius||Description of the Test|
|ASME Section IX-17||Fig. QW-466.2||Fig. QW-466.3||Para. QW-160|
|API 1104 2013||Fig. 8||NA||Para. 5.6.4, 5.6.5|
|AWS B2.1:2014||Fig. A.5A||Fig. A.5C||Para. 4.7.6|
|AWS D1.1:2015||Fig. 4.8 to 4.11||Fig. 4.8 to 4.12||Para. 188.8.131.52|