Method for producing large-specification circular blanks in rolling mode instead of forging mode

Abstract

The invention relates to a method for producing large-specification circular blanks in a rolling mode instead of a forging mode. The method mainly comprises the following steps that 1, rough rolling pass designing is conducted, specifically, rough-rolled holes are a combination of flat holes, box-type holes and intermediate billet finished holes; 2, firstly, the heating time before rough rolling is prolonged, secondly, the pass reduction of the front passes is made to be small while the pass reduction is increased in later passes in order to ensure rolling stability, and thirdly, the tapping temperature is improved, the number of rolling passes is reduced by adjusting the pass reduction; 3, firstly, two-radius oval holes with small long axes and short axes are adopted as finishing pass before finished products are formed, and secondly, circular holes are adopted as last pass for rolling; and 4, firstly, the position of the blanks in a furnace is adjusted, and it is ensured that the temperature difference of surfaces of the blanks is within 30 DEG C, secondly, the control mode of cooling water of a roller is adjusted, and thirdly, the assembly quality requirement is determined, quantitative management is conducted, and the assembly quality of a tool is ensured. The forging mode is replaced with the rolling mode through improvement of the rolling process and selection and designof the rolling mill passes, and the product competitiveness is improved.

Description

technical field [0001] The invention belongs to the technical field of rolling technology in the metallurgical industry, and in particular relates to a production method for large-size round blanks by rolling instead of forging, which is mainly used for producing products with high compression ratios. Background technique [0002] Rough rolling is a reciprocating rolling mill, which mainly produces intermediate billets. The 600-round billet is rough-rolled. The main problems are: 1. When the large round billet is rolled, it is easy to fall steel, because it is in contact with the roller table, The contact surfaces of the rolls are all arcs, and it is not easy to support; 2.600 circles are heated in the furnace, if the heating is not good, it is easy to produce a large temperature difference between the surface and the center, between the longitudinal and horizontal directions, which is not good for the uniformity control of deformation; 3. Due to the limitation of the capaci...

AI Technical Summary

Problems solved by technology

[0002] Rough rolling is a reciprocating rolling mill, which mainly produces intermediate billets. The 600-round billet is rough-rolled. The main problems are: 1. When the large round billet is rolled, it is easy to fall steel, because it is in contact with the roller table, The contact surfaces of the rolls are all arcs, and it is not easy to support; 2.600 circles are heated in the furnace, if the heating is not good, it is easy to produce a large temperature difference between the surface and the center, between the longitudinal and horizontal directions, which is not good for the uniformity control of deformation; 3. Due to the limitation of the capacity of the rolling mill, the amount of reduction in a single rolling pass is limited, and the extension deformation of the material is only on the surface, and the central deformation does not penetrate, and it is easy to produce surface wrinkles; 4. Due to the large billet, in order to ensure the size of the intermediate billet , there are many rolling passes, and the temperature drop of the billet is relatively large, which has a great influence on the load of the finishing mill

[0003] Another prominent problem in bar rolling is head bending. This problem is easy to cause cold bars to be rolled, and second, it is relatively difficult to straighten and the bending range is small.

The main reasons are as follows: 1. When the billet is heated, due to the position in the furnace and the heating position of the burner, there is a temperature difference in the longitudinal and transverse directions of the billet, and the bending is caused by the difference in elongation during rolling. ; 2. Due to the location of the cooling water, it has an impact on the wear of the roll and the cooling of the steel, resulting in different contact surface friction and bending; 3. Due to the assembly quality of the tooling, the control of the size of the tooling during rolling and the rolling The bending is caused by the control of the center line and other reasons

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