cracks in casting of copper alloys

Are the 'Cracks' longitudinal or transverse? radial? on ends ? how are billets cut off? what is mold oscillation frequency? what are the alloys? does it occur on all grades or only certain grades? What is superheat? What is caster type? How many strands? all strands or only some? What is caster speed? what is radius or is this stick caster? all sides of the billets or not? limited to certain molds? or all molds? what are you using for mold powder? What is flow rate of water to molds? Are their aspirations and entrainments of mold powder or other expogenous inclusions associated with some, many, or all of the cracks? Have you used a microscope to make sure? do your alloys meet standards for tramp and residual elements or may they be a factro as well? Are these alloys leaded, tellurium treated, or bismuth treated?

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milo

Its probably due to heat lateral heat transfer. Try using moulding powders or increae the melt temperature and see what happens.