In EPC, the prevention and cure of carbon defect of steel castings can be carried out in the following aspects:
(1) Choose low density mold material. Using EPS time pattern density control at 0.016~0.025 grams per cubic centimeter, switch to low carbon mold material EPS (C8H8) to Epmma (C5H8), so as to reduce the carbon content of the appearance. The hollow structure and hollow structure gating system can also be used.
(2) suitable pouring temperature and pouring speed, the setting of gating system determines the flow and velocity of molten steel; the pouring temperature increases, the pouring speed also increases, the mold material decomposition accelerates, is not easy completely gasification, the product medium liquid quantity also increases, at the same time, the steel liquid and the appearance gap reduces, the liquid phase decomposition material often is squeezed out the gap, squeezes to the coating and the metal industry, As the contact surface increases and the carbon concentration increases, the carburizing capacity increases.
(3) Choosing reasonable pouring process. Mold and pouring process design to be able to accelerate mold gasification, reduce and stagger the decomposition products in the liquid phase and solid phase contact and reaction time, can reduce or avoid steel parts carburizing.
(4) To improve the permeability of the coating or dry sand mold, the better the permeability, the faster the product of the decomposition of the die material, thus reducing the concentration and contact time of the dissolved matter in the gap between the molten steel and the appearance.
(5) Adding additive (decarbonization agent) in the appearance to prevent the steel casting carburizing.
(6) The use of precision molding mold in line with the casting process.
(7) Use of anti-carburizing paint.
Previous: Heat treatment of precision castings