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Anviloy Wire - H13 Cladding Development

Kovacich, Jerry Lee
http://rave.ohiolink.edu/etdc/view?acc_num=osu1607006709167907

Abstract Details

2020, Master of Science, Ohio State University, Welding Engineering.
High pressure die casting is used to quickly and repeatably manufacture high volumes of aluminum parts with good surface finish. Thermal fatigue cracking (heat checking) from thousands of thermal cycles, local soldering of aluminum part features to the surface, and buildup of lubricant residue leads to damage of die surfaces. Manual repair of hot work tool steel (HWTS) dies using arc welding is burdensome, involving high preheats and post weld heat treatment (PWHT) to restore HWTS properties. Improved automated repair procedures and materials are necessary to reduce die casting costs. This effort focused on developing automated arc welding repair procedures, characterizing clad deposit microstructure, evaluating tempering effects in the H13 heat affected zone (HAZ), and cladding shot block dies for in-plant trials using an experimental Anviloy (W-27.5Ni-12.5Fe) alloy wire on H13 HWTS dies. Mechanized hot wire gas tungsten arc welding (HW-GTAW) procedures were developed to produce low dilution single and double layer deposits. The minimum weld dilution with HW-GTAW required to produce sound clads was 18%. HW-GTAW trials showed that consistent, sound Anviloy wire clads could be deposited onto H13 using arc welding. Robotic gas metal arc welding pulse (GMAW-P) procedures were developed for conformal cladding the shot block. The robotic GMAW-P system provided better accessibility to accommodate shot block features. Both a DC+ and DC- advanced waveform were evaluated, but only the DC- waveform resulted in stable and sound deposition of Anviloy wire consumable. The die block’s complex shape mandated the use of sub-optimal torch angles when cladding in the 2G position. Work angle oscillation was used to improve bead shape in these adverse torch positions. A weld stop procedure was developed to improve conformal cladding complex shapes. The developed two layer cladding procedure minimized number of weld passes and amount of deposited material needed to create a 10mm clad layer repair. These trials verified GMAW-P could be used to conformally clad H13 using Anviloy wire. Single layer GMAW conformal cladding procedures will require PWHT since the deposits are too thick for temperbeading. HW-GTAW heat input and preheat effect on H13 HAZ size was related to HAZ tempering effects on double layer deposits. H13 HAZ lengths were measured using metallography and verified with hardness mapping. Reduced preheat at 25kJ/in heat input were found to produce preferred HAZ conditions for tempering H13. Hardness maps comparing double layer non-temperbead to temperbead double layer clad deposits revealed reduction of hardness indents over 600HV from 15% to only 1%, respectively. These results indicate feasibility for implementing temperbead weld repairs of HWTS dies using the GTAW process. Since no prior literature was published on the W-27.5Ni-12.5Fe weld clad microstructure, characterization was used to understand effects of cladding procedure on fusion and HAZ microstructures. Metallography, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Thermocalc simulation software were used to identify potential phases present. Undiluted fusion zone microstructure was composed of gamma Ni-Fe FCC matrix phase and secondary alpha tungsten BCC phase. Upon dilution with H13, a third phase was observed in SEM and EDS analysis. Thermocalc simulations indicated this phase could potentially be an intermetallic Mu phase or M6C carbide. An additional cladding procedure was developed using a butter layer of 308L between the Anviloy wire and H13 to help investigate the deposit phases. The Anviloy-308L butter clads were subjected to H13 normalization and double temper heat treatment. Attempts to identify the unknown phase with EDS were inconclusive. Metallography using selective alkaline sodium picrate etchant indicated that the unknown phase was likely M6C.
Dennis Harwig (Advisor)
Boyd Panton (Committee Member)
207 p.
Engineering; Materials Science; Metallurgy
Ni-W-Fe; Refractory Alloy Cladding; Die Repair Welding; Hot Work Tool Steel; H13; Temperbead Welding; Temperbead Repair of H13; High Pressure Die Casting Materials; Die Materials; Automated Die Repair; Conformal Cladding; HW-GTAW

Recommended Citations

Citations

  • Kovacich, J. L. (2020). Anviloy Wire - H13 Cladding Development [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1607006709167907

    APA Style (7th edition)

  • Kovacich, Jerry. Anviloy Wire - H13 Cladding Development. 2020. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1607006709167907.

    MLA Style (8th edition)

  • Kovacich, Jerry. "Anviloy Wire - H13 Cladding Development." Master's thesis, Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1607006709167907

    Chicago Manual of Style (17th edition)

osu1607006709167907
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