wall thickness, still allowed for posi- tive pressure test results even with less than desirable metal structure (Fig. 2). Te pressure tests resulted in almost no failures for leaking. Testing of tensile bars poured dur-
Fig 2. This is an example of a gas pocket found in a casting made from C83470.
ing the trials resulted in mechanical properties that exceeded the published mechanical properties of C83470. Table 2 shows example tensile bar results from the trials. Castings made from the C83470 material were very ductile.
Leachate testing was conducted on
multiple waterworks ball valve assem- blies. Te valve sizes ranged between 0.625-2 in., with all passing the NSF/ ANSI Standard 61-G requirements.
Recyclability Comprehensive recyclability of the
current low-lead alternative family of alloys has been an industry-wide concern for recyclers, ingot makers and metalcasting facilities. Tis issue
C83470 SUCCESS IN GREEN SAND JOBBING FACILITY
Richmond Industries, Dayton, New Jersey, started pour- ing C83470 for production in 2014. It is a green sand jobbing facility currently using alloy to pour waterworks fittings and heat exchangers. Typical casting weights range from 1.5-20 lbs., and wall thick- nesses range from 0.19-0.5 in.
The advantages, according to Richmond Industries’ experi- ence, include the fact there are no gating changes and it uses non-pressurized gating systems, as with other low-lead alloys.
The metalcaster also experienced a good surface finish and no burn-in at elevated pouring temperatures. Scrap is reduced and pressure tightness, casting color and brazing and soldering capability are good. No machining problems have occurred, and the metalcaster has no concern passing NSF lead or bismuth leach tests. Recyclability is also a plus. According to Keith DiGrazio, president, Richmond Industries, the company does not see any disadvantages with C83470 and would like to switch more its customers to C83470.
38 | MODERN CASTING February 2016
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