Summary for aluminium wire rod surface problem Discussion
Aluminium wire rod surface problem is described as a hard, black, patchy layer forming on some coils during storage, especially in the rainy season, and causing trouble in wire drawing and premature die damage. Manasa Mishra of Nagar, Orissa, India asked what the coating might be and noted it appears after storage rather than immediately after rolling. Tom Pullizzi suggested first characterizing the black coating to determine whether it is organic or inorganic, testing whether it burns or leaves residue, and tracking when affected coils were poured and drawn to look for a timing pattern. A later reply from Rebel 55 Student said the issue is due to oxidation from long exposure to moisture and advised checking that water is not carried over after quenching, not packing hot coils, and improving storage conditions. The thread therefore points to moisture control and handling/storage practices as the practical fix, while also recommending analysis if the cause is still uncertain.
Q. I work in an Aluminium smelter in Eastern India. We have an aluminium hot rolling mill supplied by Properzi. In some of the coils, a hard & black layer is getting formed. The black layer is not on the full coil but in patches. This is creating difficulty in wire drawing process. The drawing dies are getting prematurely damaged due to this. The black layer is getting generated during storage. The problem is more common during the rainy season.
Manasa Mishra
– Nagar, Orissa, India
2000
A. Have you tried to characterize the black coating as to organic or inorganic? Does it burn?, does it leave a residue upon ignition? What is its melting point? Have you charted the occurrence of the black coating along a time line for a year? with * for date the aluminum was poured, and # for date the coil was drawn.
J—F—M—A—M—J—J—A—S—O—N—D
————*———–#
—–*——#
—————————-*———–#
or something like that. This might be helpful even if you can get a sample of the wire to a university for analysis.
Tom Pullizzi
Falls Township, Pennsylvania
A. It’s due to oxidation, long exposure to moisture.
1) Check your machine after quenching: water should not get carried with rod.
2) Don’t pack hot coil
3) Check your storage area
Rebel 55
Student – India
May 8, 2023
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