This paper summarizes a paper, entitled “Resistance Welding Projection Methodologies as Applied to Hot-Stamped Boron”, by D. Crist, et al.C-11
The study focuses on two different Resistance Projection Welding approaches and compares the welding parameters, mechanical properties and destructive results. Table 1 lists the secondary impedance measurements and Table 2 lists the material information for the PHS-CR1500T-MB-AS.
The thickness of the material chosen was 1.80 mm and the weld coupon dimensions are shown in Figure 1.
The projection weld nut used for testing is an M6 hex flange, three projections, non-piloted weld fastener. Detailed dimensions are shown in Figure 2.
Table 3 lists the weld schedule methodologies tested in this study. Table 4 shows the optimized weld schedules based upon push-off strength and visual weld flash level.
Repeatability testing for both Methods A and B are shown in Figures 3 and 4. The data produced for Method B shows a higher average of repeatability.
Two different failure methods were observed. Figure 5 shows full thickness buttons were pulled thought the flange for Method A and Figure 6 demonstrates partial thickness failure for Method B.
Figure 7 shows the microhardness traverse results for both Methods A and B. Method A yields a much larger HAZ. Method B shows a much smaller HAZ, less impact on the base material, and appears to be a solid state bond.