tions as a means of comparing the two regions. The profile of one of the specimens away from the weld area is shown in Figure 14. It also should be noted the scale of the y-axis differs significantly from the x-axis. As can be seen, numer- ous peaks occur along the entire specimen length due to the as-cast surface condition.
Figures 15 & 16 illustrate the surface profile of the sample ex- tracted from within the weld area, with the defect located approx- imately in the center. Figure 15 shows the entire length of the surface with the weld between 70-80 mm along the x-axis.
In order to better examine only the de- fect, a separate profile image was taken in a smaller, 3-mm region around the weld. The weld descends into the thick- ness of the plate in the negative y-di- rection in several locations, such as ap- proximately 40 microns at 1.5mm, 50 microns at 1.75mm, and 100 microns 1.85mm (Figure 16). Further visible inspection of the surface within the af- fected region revealed the valleys cor- respond to an area in which the weld separates into several divergent paths.
Within this same 3 mm region, an area scan also was performed. These three- dimensional images are produced by scanning along both the x- and z-axes. The features of this area, in particular the peaks of Figure 16, are shown in greater detail in Figure 17.
Figures 15-17 show the maximum in- trusion of the weld is approximately 100 microns, but taking into consider- ation the 10 mm thickness of the plate, this depth confirms previous conclu- sions that the confluence weld was a superficial defect.
Four-Point Bend Tests - Set 1 In this section, the results of the initial four-point bend tests on one B and A1 plate are presented and discussed.
The two samples from the A1 plate fractured within the central span, as is expected with the method of four- point bend test, but only one of the specimens broke directly in the middle of the points of application of the two forces (Figure 18).
Of the eight samples tested from the B configuration (Fig- ure 8), only one of the samples (B-C1) fractured within the weld, although all samples did fail within the central span. Only one fractured specimen is shown in Figure 19, depict- ing the approximate locations of failure for the majority of the samples. Highlighted in red is the location of the confluence weld.
Figure 14. Surface profile of sample (B-10_3) away from affected area along length of sample.
Figure 15. Surface profile of sample (B-4) within defected area along length of sample.
Figure 16. Surface profile of sample (B-4) within 3mm area along length of weld.