Exposed gear casting no-choke riser-head technique design

Abstract

The invention provides the technological design for manufacturing an unobstructed shrink head for an exposed gear. The technological design includes the following processes of: metal allowance setting; positive quantity correction; sand core; shrink head; shrink head sleeve; chilling block stuccoing; casting system; wood model manufacture; molding and core making; case buckling; casting; heat insulating covering agent adding; heat insulation and cooling of the casting; clearing; heat treatment; burnishing; heat treatment for the second time; mechanical capacity performing; roughcast dispatching; rough machining; UT fault detection; secondary heat treatment; finish machining and tooth washing; and MT fault detection; surface polishing of the casting, and the like. The technological design has simple processes and good feeding effect, which completely overcomes the defect of the shrinkage porosity of the shrinkage cavity under the shrink head and the shrinkage porosity between the shrink heads; and by UT and MT fault detections, the qualification rate reaches 100 percent.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a process design of an open gear casting non-impeding flow riser. Background technique [0002] Open gear castings are widely used in large-scale cement, mining, metallurgical and other equipment. At present, the open gears produced mainly involve industries such as rotary kilns, raw material mills, autogenous mills, dryers, and converters on non-ferrous metallurgical equipment. [0003] The purpose of setting risers in steel castings is to make the molten steel in the risers flow into the body continuously during the solidification process of the castings, so as to supplement the molten steel, so that the castings can get enough molten steel to achieve a dense internal structure, and the UT and MT inspections are qualified. [0004] In the past, the riser design of the open gear is that the outer rim riser adopts a cylindrical open riser, and the joint surface adopts...

AI Technical Summary

Problems solved by technology

[0006] 1. The process design is cumbersome, and there are many factors affecting the calculation of thermal joints, so it is difficult to accurately calculate the size of the riser. As a result, different people will have different results in the design, or the same person will design the castings with different structures, and the final casting quality will also appear. different results

[0007] 2. Improper setting of the diameter of the riser or the distance between the two risers will cause shrinkage cavity under the riser and shrinkage porosity between the risers

[0008] 3. Once the casting has shrinkage and porosity, the UT flaw detection is unqualified. If it is light, it will be dug and welded, and if it is serious, it will be scrapped. The UT flaw detection failure rate is as high as 20-30%.

[0010] 5. The lack of dense grain structure inside the ring gear is directly related to the dispersed riser of the existing process