| 摘要 |
FIELD: metallurgy. ^ SUBSTANCE: molding sand contains binding material and fluorine-free composition including isolating refractory matter and exothermal mixture. The last contains oxidized compound, oxidizing agent and magnesium. At making insert molding sand is blown to cold box with two cores and it is solidified with use of catalyst. Hole open at both sides is formed in insert by means of cores. Solidified insert is extracted out of cold box and plug made of plastics, wooden material, saw dust, paper, sand or insert material is placed at one end to said hole. ^ EFFECT: improved quality of castings. ^ 11 cl, 6 dwg, 1 tbl |
