And the reasons that caused the precision casting solution
Release Time::2014-09-03
Porosity is one of the common defects of precision casting, precision casting porosity refers to individual location to appear smooth holedefects. Porosity can often found after machining. Yanzi precision casting technicians with many years production experience, the causes and prevention methods of stomata appeared in precision casting are summarized as follows: A, forming reason: hole 1 in most cases mainly because of inadequate precision casting shell roasting, pouring molten steel shell the moment a large amount of gas can not be successfully discharged, and penetrating blowhole the formation of metal liquid; 2 forshell making process or shell material, shell permeability is poor, it is difficult to discharge the gas in the cavity, pore forming into the liquid metal in the molten steel pouring; 3 involved in the air can not be discharged to cause the blowhole. Two, 1 in the prevention methodsallow precision casting conditions, the exhaust holes in castings topcomplex structure. 2 in the design of gating system, should give full consideration to the shell exhaust demand. 3 shell roasting temperature,time should be reasonable, holding time should be sufficient. 4 dewaxingwax material should be eliminated. 5 appropriate to reduce the ladlenozzle to the pouring cup distance, casting speed should be uniform, to ensure the stability of steel level filled cavity, air into molten steel as little as possible, so that the cavity gas and molten steel can be discharged smoothly.