ASTM B418-01 pdf free.Standard Specification for Cast and Wrought Galvanic Zinc Anodes.
The anode shall be made from Special High Grade zincconforming to Specification B 6, with suitable alloying addi-tions for Type I anodes.Composition of the anode alloy contentshall conform to the limits prescribed in Table 1.
Evidence from laboratory tests shows that Type Icomposition may suffer intergranular corrosion. Susceptibilityto intergranular corrosion increases with increasing tempera-ture and is particularly severe above approximately 120°F(50°C). Intergranular corrosion can be avoided (at tempera-tures above about 120°F) with Type I composition,whichmust be made from special highgrade zinc with an ironcontent well below the 0.003 % maximum given in Specifica-tion B 6.Methods of Chemical Analysis: The chemical compositions enumerated in this specifi-cation shall,in case of disagreement,be determined bymethods mutually agreed upon or the methods listed in Table 2approved for referee purposes by ASTM. Test Methods E 536shall be used, except for Type IL.For anodes with integral inserts intended for attachmentby bolting, it is recommended that a bolt-hole spacing of 6 in.(152 mm) or even multiples thereof be used. Anodes with projecting rod inserts threaded for attach-ment by means of a bolted connection shall have UnifiedNational Coarse threads.
Workmanship，Finish, and Appearance:The zinc anodes shall be free of flash，burrs，cracks,blow holes, and surface slag, consistent with good commercialpractice.Cast anodes shall not have shrinkage cavities exceeding l/a the depth of the anode or 1 in. (25.4 mm), whichever issmaller when measured from a straightedge placed diagonallyacross opposite edges of the anode.Drill holes and saw cuts for sampling shall not be cause for rejection unless they are severeenough to cause premature failure of the anode.The sample for chemical analysis shall be taken asfollows:A number of anodes shall beselected at random to give a representative sample of the lot.Alot shall consist of not more than 20 000 1b (9070 kg) of zincanodes cast from a single melt or not more than 5000 1b (2268kg) of anodes cast in a single 24-h period from more than onemelt. The minimum number of anodes to be sampled shall beas specified in Table 3.Each selectedanode shall be sampled by drilling or machining with anonferrous tool.The use of a drill with a tungsten carbide tipis recommended. The tool bit or drill shall not penetrate intothe core material or a cored anode.The cuttings from all anodesin a lot shall be thoroughly mixed to form a uniform sample ofnot less than 50 g total.Claims to be considered shall be made in writing to themanufacturer within 30 days of receipt of anodes at thepurchaser’s plant and the results of the purchaser’s tests shallbe given.The manufacturer shall be given one week from dateof receipt of such claim to investigate his records and then shallagree either to satisfy the claim or send a representative to theplant of the purchaser.ASTM B418 pdf download.