Forging control method for uniformly refining grain sizes of forgings

Abstract

The invention relates to a forging control method for uniformly refining grain sizes of forgings. Special forging control and furnace return heating modes are adopted in the forging process of large forgings, so that the surface and heart temperatures of the forgings tend to be consistent, the heart structures of the forgings are totally transformed, and the internal structures of the large forgings are uniformly refined; the before-forging high-temperature heating is adopted; after first heating number upsetting and lengthening forging, the forgings are cooled in air to reach a certain temperature; after the internal and external surface temperatures of the forgings tend to be consistent, the forgings are returned to the high-temperature furnace for heating; after second heating number upsetting and lengthening, the forgings are cooled in air to reach a certain temperature; after the internal and external surface temperatures of the forgings tend to be consistent, the forgings are returned to the low-temperature furnace for heating; the forgings are discharged from the furnace for forging after insulation in the low-temperature furnace by a period of time; and the forging controlmethod can uniformly refine the internal structures of the large forgings under the condition of not increasing the production cost, solves the difficulties of coarse crystals and mixed crystals of the large forgings, greatly reduces the production cost, shortens the production period, and is high in mechanical performance index of the forgings, long in service life and more economical and scientific in production process.

Description

technical field [0001] The invention belongs to the field of iron and steel material manufacturing process control, in particular to a forging control method for uniformly refining the grain size of forgings. Background technique [0002] The forging of large forgings usually requires upsetting, elongation, and multi-fire forging. After each fire forging, the core temperature of large forgings is still high, and the billet is directly returned to the high-temperature furnace for heating, resulting in long-term high temperature in the core. state, the internal structure cannot be fully transformed, so the core structure of the forging is coarse, and the whole forging is coarse grained and mixed grained. [0003] At present, the problem of coarse grains and mixed grains has always been a major problem in the production of large forgings, especially for CrNi2MoV, CrNi3MoV, CrNi4MoV steels, this problem is more prominent. Coarse and uneven grain size not only affects the ultras...

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Problems solved by technology

[0005] The purpose of the present invention is to use a special forging control method to solve the problem of coarse grains and mixed crystals in large forgings without increasing production costs, to obtain uniform and fine internal structures, and to improve the impact energy of products. Control the forging process and return to the furnace heating method to improve the forging control method of large forging grain size uniform refinement of forging grain size, this method greatly improves the pass rate of large forging grain size, and then solves ultrasonic detection clutter and mechanical properties Low-level problems, this method also greatly reduces production costs, this method is not only suitable for CrNi2MoV, CrNi3MoV, CrNi4MoV and other types of steels that are prone to coarse grains and mixed crystals, but also for other types of steel large forging products

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