in. maximum, and that it often closes during welding. Figure 1 from AWS B2.1-1/8-010:2015 (Fig. 2) allows for a root opening of up to the maximum thickness of the two members of the joint. Since the base metals are about 1⁄8 in. thick, a 1⁄8-in. root opening would be within the limits of this SWPS. The root opening would need to be maintained by frequent tacks to prevent closing that results in higher dilution. Another approach would be to grind or machine a single V-groove or single bevel joint preparation so that more filler metal would be required to fill the joint. If a single bevel is used, I would recommend putting the bevel on the carbon steel side so that more dilution comes from the 304 side than from the carbon steel side — that would move the point labeled “Mix of Base Metals” to the right in Fig. 1 and would thereby increase tolerance for dilution in the joint. I note that a V-groove or bevel groove joint preparation is not within the SWPS mentioned, so the inquirer would need to write a new WPS. The inquirer’s experience demonstrates a limitation of simply following a SWPS. As stated in the clause titled “User’s Responsibility” in AWS B2.1-1/8-010:2015, “The ability to produce production welds having properties suitable for the application depends upon supplementing the SWPS with appropriate performance qualification tests and sound engineering judgment.” Sound engineering judgment would certainly entail limitation of dilution as described above. Reference 1. Kotecki, D. J. 2000. A martensite boundary on the WRC-1992 diagram — Part 2: The effect of manganese. Welding Journal 79(12): 346-s to 354-s. 20 WELDING JOURNAL / JULY 2016 WJ DAMIAN J. KOTECKI is president, Damian Kotecki Welding Consultants, Inc. He is treasurer of the IIW and a member of the A5D Subcommittee on Stainless Steel Filler Metals, D1K Subcommittee on Stainless Steel Structural Welding; and WRC Subcommittee on Welding Stainless Steels and NickelBased Alloys. He is a past chair of the A5 Committee on Filler Metals and Allied Materials, and served as AWS president (2005–2006). Questions may be sent to Damian J. Kotecki c/o Welding Journal, 8669 NW 36 St., # 130, Miami, FL 33166, or via email at damian@damiankotecki.com. For info, go to aws.org/adindex
Welding Journal | July 2016
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