Internal chill process for improving shrinkage porosity of vermicular iron cylinder head

Abstract

The invention discloses an internal chill process for improving shrinkage porosity of a vermicular iron cylinder head. The internal chill process comprises the following steps that the internal chillis used for chilling from the inside of a casting hot spot when the vermicular iron cylinder head is produced, wherein the internal chill needs to be placed in a cavity and kept fixed during casting,and the internal chill and molten iron can be fused into a whole during pouring; the internal chill is fused with the casting and is removed during machining; the internal chill is placed in a bolt hole part and inserted into a sand core base to be fixed; the internal chill is placed in a fuel injector hole, is wrapped in a sand core during sand shooting, and is fused with the molten iron into a whole during pouring; and the internal chill is made of low-carbon steel. According to the internal chill process, the internal chill made of the low-carbon steel is fixed to the center of the hot spotpart in a certain modes, chilling is directly conducted from the center part where shrinkage porosity is likely to occur, the action effect is high, and the chilling effect is good; compared with chillers currently used in the industry, the internal chill is smaller in size, lighter in weight and more convenient to use in the production process and transport in a logistics mode.

Description

technical field [0001] The invention belongs to the technical field of casting, and relates to an internal cooling iron process for improving shrinkage porosity of vermicular iron cylinder heads. Background technique [0002] At present, the common problem of high-grade vermicular iron cylinder heads (grade higher than Rut400) is that parts with thick structures such as injector holes and bolt holes are prone to shrinkage casting defects. It can only be found by the integrity test. At present, in the industry, the problem of shrinkage and porosity in thick and large parts is often solved by feeding the riser process and chilling with external cooling iron. The riser process is costly and its applicability varies from product to product. The external chilled iron process has a limited chilling effect on the central area of ​​thick and large parts and cannot completely eliminate shrinkage porosity. The inner cooling iron process is to fuse the inner cooling iron made of low ...

AI Technical Summary

Problems solved by technology

[0013] The technical problem to be solved by the present invention is to overcome the problem of insufficient chilling effect of cold iron on casting hot spots in the prior art, and to provide an internal cooling iron process for improving shrinkage porosity of vermicular iron cylinder head

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