Method for casting large main-bearing seat

Abstract

The invention is concerned with molding method for large tape of headstock seat, relating to workout molding technology, make wood mould, make sand casting, close box, molding, cooling and clear casting. Workout molding technology to produce headstock seat by plot out the plane of mould and make wood mould according to the process demand and locate the wood mould on the mould plane. Make casting mould and set cold iron and close box to dry sand casting. Melt casting mould liquid and during the melting process, blow inert gas and feed the wire. Pour the casting, keep temperature and carry heat treatment by routine method. This method takes exothermic risers with same number of moulds to replace the existing micro - particle riser, and this saves the pouring amount of melting liquid and avoids the limitation of shrinkage of the shaped cold iron when it is on the surface of bearing hole. When during the pouring, it forms the anaerobic condition to enhance the purity of steel water and the produce of impurity between two oxidations and the dissection capability of thick part of casting is satisfied.

Description

technical field [0001] The invention relates to material forming, in particular to a casting method of a large main bearing seat. Background technique [0002] The bearing seat is a high-demand steel casting on a diesel engine. According to the technical specifications of the low-speed diesel engine patent company, the material of the casting is: S17F, and the performance requirements of the test bar before the furnace: the tensile strength is 440-540N / mm 2 , yield strength ≥ 260N / mm 2 , elongation ≥ 22%, reduction of area ≥ 30%; Brinell hardness 130-160. After the casting is processed, magnetic particle testing (MT) and ultrasonic testing (UT) are required. The casting must not have cracks, pores, cold shut, shrinkage porosity, trachoma and other casting defects that affect the compactness of the casting material, especially when it is in contact with the crankshaft. There must be no crack defects in the saddle part, otherwise the steel casting will be scrapped. [0003]...

AI Technical Summary

Problems solved by technology

[0004] According to the actual production situation for many years, the existence of this casting method has the following disadvantages: 1) sticky sand is easily produced under the riser

2) The thermal insulation effect of the riser is poor

3) Both sides of the riser in the bearing hole are prone to cracks and other defects

4) Large castings are prone to deformation

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