Accelerated cooling process of quenching machine for enhancing intensity of normalized steel plate

Abstract

The invention discloses a quenching machine accelerated cooling process for improving the strength of a normalized steel plate, which belongs to the medium plate normalization control cooling technical field. After the normalized steel plate is taken out from a quenching furnace, the normalized steel plate enters a quenching machine along with a roll table of the quenching machine for hydrocooling, the speed of the roll table of the quenching machine is controlled to between 10 and 25m/min, and water amount control parameters are as follows: the water amount of district 13 of a high pressure section of the quenching machine is between 2.5 and 3.3m<3>/min; the water amount of district 14 is between 3 and 4m<3>/min; the opening degree of a flow control valve of district 15 of a low pressure section is between 30 and 40 percent; the opening degree of a flow control valve of district 16 is between 35 and 47 percent; and the cooling speed of the steel plate is controlled to between 6 and 8 DEG C/s. The water amount, the opening degree and the speed of the roll table of each district are adjusted according to the specification of the steel plate, so that the steel plate is cooled to between 600 and 650 DEG C; the hydrocooling improves ferrite nucleation rate, inhibits the growth of crystal grains, refines the crystal grains, and improves the strength of the normalized steel plate. The process has the advantages of improving the ferrite nucleation rate, inhibiting the growth of the crystal grains, refining the crystal grains, and improving the strength of the normalized steel plate.

Description

Accelerated Cooling Process of Quenching Machine for Improving the Strength of Normalizing Steel Plate technical field The invention belongs to the technical field of normalizing and cooling control of medium and thick plates, and in particular provides an accelerated cooling process of a quenching machine for improving the strength of a normalizing steel plate. Background technique Low-alloy high-strength steel is usually delivered by controlled rolling or heat treatment and normalizing. The yield strength of low-alloy high-strength steel after normalizing process is generally 30-50Mpa lower than the strength after controlled rolling, which is often lower than the standard value. On the edge of the lower limit of the standard value. To solve the problem of insufficient strength after normalizing, the method commonly used at home and abroad is to increase the strength after normalizing by adding a large amount of solid solution strengthening alloy elements such as Cu, Cr, ...

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Problems solved by technology

The purpose of the present invention is to provide a quenching machine accelerated cooling process to improve the stre

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