Control method for reducing network cementite of steel wire rod for cord thread

Abstract

The invention discloses a control method for reducing network cementite of a steel wire rod for a cord thread and belongs to the technical field of steel rolling. The control method includes the steps of heating process control for a heating furnace in a steel wire rod factory, precision rolling and sizing milling control, water cooling control, thread discharging temperature control and air cooling line cooling process control. A precision rolling inlet temperature and a thread discharging temperature need to be specifically adjusted according to different seasons, namely controlling the precision rolling inlet temperature within 930-960DEG C, controlling a precision rolling outlet temperature to be not higher than 1060DEG C, controlling the thread discharging temperature within 860-900DEG C, adjusting openness of a Jialing device to 60%, starting the first 8 fans with 100% of fan delivery and 260KW in power, and controlling a roller way speed of an inlet section within 0.9-1.1m / s. When the controlled method is utilized for continuously casting the steel wire rod for the cord thread by short-process small square billets which are 140mm<2>-150mm<2>, the probability for happening of the network cementite at the center of the steel wire rod can be reduced by 10%-15%.

Description

technical field [0001] The invention relates to a control method for reducing mesh cementite in wire rods for cords, which is particularly suitable for the process of producing wire rods for cords by billet continuous casting, and belongs to the technical field of steel rolling. Background technique [0002] Steel cord is the most widely developed product among rubber skeleton materials, and is an important raw material for manufacturing steel wire radial tires. Generally, it is drawn from a wire rod with a diameter of Φ5.5mm to a thin wire rod with a diameter of Φ0.15-0.38mm through multiple passes. Silk, finally formed by joint stock. The wire rod for cords is a special steel type for producing steel cords, and the area reduction rate can reach more than 99% in the production process. important. [0003] At present, domestic steel enterprises mainly control the degree of segregation by controlling the superheat, casting speed and electromagnetic stirring of the continuou...

AI Technical Summary

Problems solved by technology

However, the cooling rate of water cooling after rolling is a very general concept. The influence of water cooling on cooling rate and temperature drop is not only related to the flow of water, but also related to pressure, ambient temperature, rolling speed, etc. The effect of temperature drop is a parameter that is difficult to control in the actual rolling process on site

At the same time, it is also proposed to adjust the air volume so that the cooling rate of the wire rod is controlled at 3-10°C / s. However, the Gleeble simulation in the previous laboratory shows that: in the case of segregation, when the cooling rate is 3-10°C / s, the cooling rate of the wire rod is 3-10°C / s. There will still be reticular cementite in the heart, which is unfavorable for tissue control at this cooling rate

Patent 200910169807.7 proposes a production method for high-carbon steel wire rod, which defines the rolling start temperature and spinning temperature, but does not take into account the influence of ambient temperature fluctuations on the process, and there is no specific temperature setting for flexible on-site operation. Based on

Patent 201110075816.7 proposes a method to reduce the martensitic structure in the core of high carbon steel wire rod, and expounds the heating system, rolling system and cooling system of the heating furnace, but only limits the specific temperature, and the specific implementation process It is not mentioned, and in many places, the temperature difference between winter and summer can be 20-40°C. The influence of room temperature on the properties of materials in the rolling process is a very complicated process. The influence of room temperature on the rolling process and the solutions are not Not mentioned

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