Carbon pick

Coon, P.M., "Carbon Pick-Up in Electric Furnaces," British Cast Iron Research Association Journal Report 1296 March 1978, 133. 

Table 6. Mass changes due to carbon pick-up after 1008 hours of cyclic exposure in carburising CH4/H2 gas with a carbon activity of ac=0.8...

Hanmer, H.R. Filter balances smoke. New filter has activated carbon Picks up vapor phase components Statement attributed to Dr. H.R. Hamner, Director of Research, American Tobacco Co., Chem. Eng. News 36(33) (1958) 38. 

For steel castings, coal dust is not used because of carbon pick-up. In this case, it is usually replaced by cereal binders such as starch or dextrin. 

The quality of the coke used has a direct bearing on the efficiency of cupola operations. It particularly affects the initial temperature carbon pick-up and the sulphur content of the iron. Specifying the foundry coke involves testing the following contents ... 

It may be possible that the slag formed will increase lining wear. Also the energy used in melting may increase slightly. In steel foundries, there is a risk of carbon pick-up. 

Generally aU ferrous and non-ferrous metals can be cast using thus method but is unsuitable for low and medium carbon steels due to the possibility of carbon pick up. Because the foam pattern has to decompose to produce the casting, metal pouring temperatures above 540 °C are usually required so that casting of low temperature metals is limited. 

A 77 bond forms between carbon and oxygen and, as the tt bond between the two carbons breaks, carbon picks up a proton. 

Castings are produced by different molding processes green sand, air-set sand, resin-bonded sand, rammed graphite, investment, etc. The corrosion resistance of an as-cast surface is a function of the moulding process, pouring temperature, and mold surface treatments or mold washes. Carbon pick-up and mold reactions are just two of the factors that influence corrosion resistance. The corrosion resistance of most machined surfaces will be independent of the molding process provided that 1/16-1/8 in. of material is removed. 

Comparison of the interstitial levels of the corroded welds, sound welds, base metal, and filler wire suggested that insufficient joint preparation (carbon pick-up) and faulty gas shielding were probably the main contribnting factors that caused this weld corrosion failure. Discussions with the vendor uncovered two discrepancies. 

Second, a manifold system was nsed to distribute pure argon welding gas from a large liquid argon tank to varions satelhte welding stations in the welding shop. The exact cause for the carbon pick-up was not determined. 

Failure of the nozzle weld was the result of intergranular corrosion caused by the pick-up of interstitial elements and snbseqnent precipitation of chromium carbides and nitrides. Carbon pick-up was believed to have been cansed by inadequate joint cleaning prior to welding. The increase in the weld nitrogen level was a direct resnlt of inadequate argon gas shielding of the molten weld puddle. Two areas of inadequate shielding were identified ... 

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