Anti-cracking casting method applied to cast steel part thin-thick-wall transition area

Abstract

The invention belongs to the technical field of casting, and particularly relates to an anti-cracking casting method applied to cast steel part thin-thick-wall transition area. The method is suitablefor cast steel part with the wall thickness ratio larger than 1.5, and the transition area of the thin wall and the thick wall are adopted patching type anti-cracking tie bars, and the anti-cracking and feeding effects can be achieved at the same time; according to the technical scheme, the anti-cracking casting method applied to the cast steel part thin-thick-wall transition area comprises the following steps that a, the modulus M of a heat joint at the joint of between the thin wall and the thick wall of the cast steel part is calculated; b, a feeding distance D is calculated according to the modulus M; c, the positions of the tie bars are determined according to the modulus M and the feeding distance D; and d, the size of the tie bars and the distance between the two tie bars are determined according to the length of the transition area between the thin wall of the cast steel part and of the thick wall of the cast steel part. Compared with the prior art, the anti-cracking casting method applied to the cast steel part thin-thick-wall transition area has the advantages and positive effects that the situation that the cast steel part is prone to generating crack defects at the contact position of the thin wall and the thick wall is solved; and the overall wall thickness of the cast steel part is guaranteed to be uniformly supplemented, and the overall quality of the cast steelpart is improved.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a casting method for preventing cracking in the thin-thick-wall transition region of a steel casting. Background technique [0002] In the casting process, the thin-walled and thick-walled transition areas of steel castings will generate strong stress during the solidification process, which will cause cracks in the transition areas, resulting in serious quality problems in the castings, and the internal structure of the cracks is poor. In the later repair process, it is easy to cause new defects to appear repeatedly, which seriously affects the quality and production cycle of steel castings. [0003] Due to the large size of some steel castings and the different assembly purposes of each part of the casting, there will be a difference between thin wall and thick wall. In the traditional process design, anti-cracking bars are set in the transition area between thin w...

AI Technical Summary

Problems solved by technology

In the traditional process design, anti-cracking bars are set in the transition area between thin wall and thick wall. A large number of anti-cracking bars are set on the steel parts, such as figure 1 As shown; too many anti-cracking bars in the molding process will affect the strength and surface quality of the sand mold. The pouring temperature of the steel casting is relatively high, which is 1570~1575 ° C. The surface of the sand mold is prone to sintering after being baked at high temperature; Too many anti-cracking tendons can easily lead to a decrease in the strength of the sand mold, and the large number and small gaps will cause sintering and sand sticking in this part of the casting, which will increase the difficulty of subsequent cleaning

In addition, in the process of process design, large-sized subsidies are set at the thin wall and thick wall to open the feeding channel, and cold iron is used to partition between the subsidies to reduce the number of large-sized subsidies; due to the actual production process of steel castings Affected by the external environment, raw and auxiliary materials and other factors, process feeding cannot achieve the expected purpose, which is prone to defects and affects the quality of steel castings; and the subsidy needs to be removed when cleaning the castings, which increases the workload of cleaning and machining, and improves Casting costs, while affecting the appearance quality of subsidized parts

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