ASME STP-PT-085:2017 pdf free download

ASME STP-PT-085:2017 pdf free download.Effect of Hot Wire Filler MetalAddition on GTAW Heat Input forCorrosion Resistant Overlays and its Resulting Effect on Heat-affected Zone Hardness and Toughness and CorrosionResistant Overlay Chemical Composition.
2 WELD TRIAL MATRIX — CR0 WELDS
To series of CROs were welded on each base metal for a total of four series. One series for each base metal was welded using conventional parameters where the weld metal deposition rate is approximately 2 pounds per hour. The second series far each base metal was welded using newly developed parameters which result in higher deposition rates on the order of X pounds per hour. The parameters used [or the higher deposition rates actually result in lower heat input rates, so this provided even more test data.
Welding was conducted on pipe coupons using ARC’s next generation HVT system. The welding system is capable of welding in a variety of welding positions by rotating the frame holding the turntable and welding torch. The frame can be rotated [mm 0-90 degrees. Images of the welding system in the two configurations are shown below in Figure 2-I and Figure 2-2. All of the saniples for this study were welded in the flat (1(3) position as shown in Figure 2-2.
While the plan was to run the samples at pre-established settings. there is a need to make minor adjustments. The primary2 amperage. wire feed speed and travel speed can be preset accurately; however, there is a need to make minor adjustments to the secondary’ amperage, primary voltage and secondary voltage to stabili,e operation and assure good wetting. Every attempt was made to ad ust the filler wire guide rube consistently with respect to the end of the tungsten electrode, however. minor secondary amperage and voltage adjustments arc inevitable. Similarly, the entry point of the filler wire was held constant, as much as practicable. For all of these test welds. the tiller wire was introduced at the rear of the molten pool. which is typical for hot wire feed, but different from typical cold wire operation, where the wire is most often introduced at the leading edge of the weld pool.
Parameters such as travel speed, wire feed speed. background current percentage Iof peak I. step-over, and pulse duration were preset and remained constant. A Lincoln Power Monitor was used. but the same software is incorporated into the ARC HVT system, so the amperages listed are those displayed on the HMI panel of the system. Comparison of the instantaneous energy with that calculated using the average of the peak and background amperage ssere used. Consequently. heat input race was calculated per QW409.1(a).
3.3Deposit Area Measurement
The final method used to analyze effects of different heat input rates was measurement of the cross-sectionalarea of deposited weld metal. To make this determination, two methods were used.The first was an attemptto physically measure the cross section of individual beads with mechanical measurement devices. Thisproved to be both difficult and subject to measurement errors. It was also influenced by the varying amountsof dilution present making it difficult to develop clear relationships.
The second method, referred to here as the Jackson Method, was named after a former Welding Engineeringprofessor，Clarence E. Jackson.Professor Jackson spent much of his professional career studyingsubmerged arc welding(SAW) and developing SAw fluxes. In a number of his studies，he was quitesuccessful in developing relationships between weld bead area and weld metal properties. In many cases,he was able to find much closer correlation between weld bead area and weld mechanical properties thancould be found using conventional heat input rate. When Professor Jackson was doing this work, the mostaccurate measuring instrument in a lab was typically an analytical balance.This method involvedphotographing a weld cross section, cutting sections of the weld deposit, and then comparing the weight ofthe weld cross section with that of a known area of the photo.