Galvanized Welded Pipe

Tensile Testing

In order to measure the strength of the pipe material, a set of three sub-size tensile testing specimens were tested. The specimens were cut longitudinally of a pipe piece. Sub-size tensile specimens were chosen to account for the pipe curvature. Geometry, dimensions and orientation of the tensile specimens are shown in Fig. 1.

Figure 1 Sampling the tensile specimens of the tube: (a) and the specimen's geometry and dimensions and (b) specimen orientation.

Structural integrity of welded structures depends largely on the mechanical properties of the weld metal. In order to measure the strength of the weld metal, used in the current study, a bock of weld metal was manufactured by a series welding beads deposited one above another, see Fig. 2a. Careful cleaning of the weld surface after each bead was done. The used welding electrode was designated as AWS E 6013. Standard tensile testing specimens were cut out of the weld metal block in the welding direction, see Fig. 2. Those specimens were then tested on a universal testing machine.

All the tensile testing of the pipe material and on the weld metal was carried out on a universal testing machine TM-300 with dual-column, stand-alone system with 300 kN maximum loading capacity.

Pipe Bending Testing

The welded pipes were subjected to bending tests. The pipes were cut longitudinally to four equal segments, as shown in Fig. 3. This is to ease the testing procedure and to characterize the difference between bending through the face and bending through the root. Fig. 4 illustrates the experimental setup for the three-point bending tests. Geometry and dimensions of the pipe specimens along with the bending test layout are shown in Fig. 5. The face- bending test was performed such that the weld face was on the outside of the bend radius. The root-bending test was performed such that the weld root was on the outside of the bend radius.

Figure 2 Sampling the tensile specimen of the weld metal. (a) In-house made block of weld metal. (b) Sampling the specimen out of the weld metal block. (Dimensions in mm)

Figure 3 Sampling of bending specimen of the welded pipes