Phi 500-650mm Cr6 type forged-electroslag-steel cold-rolled work roll blank forging and deforming technology

Abstract

The invention discloses a Phi 500-650mm Cr6 type forged-electroslag-steel cold-rolled work roll blank forging and deforming technology. The technology includes the steps of converter producing plus LF refining plus VD vacuuming, continuous casting of round blank, hot annealing of electronic blank, clearing, electroslag remelting, annealing of electroslag ingot, forging and annealing after forging, wherein four-fire mode production is adopted in forging, upsetting and drawing out deformation methods are adopted in the first fire time, forging under great pressure is adopted in the second fire time, and forging to forming in the third and fourth fire time. Temperature and heat preservation time in high-temperature diffusion are key to control in forging, furnace return temperature and time in each fire time of forging and deformation and final forging temperature of each fire time are controlled. The spheroidized structure of the produced Cr6 type forged-electroslag-steel cold-rolled work roll blank is 2-3 in grade, carbide mesh is less than or equal to 2.0 in grade, carbide strap and liquation are below 1.0 in grade, total non-metallic inclusions is less than or equal to 2.0 in grade, flaw detection eligibility rate is increased from original 75% to 95%, carbide distribution is small and diffused, and long service life is achieved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and relates to a Cr6 type forged electroslag steel cold-rolled work roll billet forging deformation process. Background technique [0002] Before 2008, the cold-rolled work rolls used in China were mainly Cr2, Cr3 and Cr5 series. In order to promote the replacement of steel for domestic cold-rolled work rolls and improve the wear resistance, roughness retention and Roll printing performance. Since 2008, Beiman Special Steel has cooperated with Baosteel Roll Company to produce and develop steel for cold rolling work rolls containing Cr6%. The alloy content of the roll blank of this steel type is relatively high, and the carbide segregation is heavy. Especially for the large-size roll blank, it is difficult to meet the requirements of ultrasonic flaw detection, and the production pass rate is low. [0003] The Cr6% type roll billet is based on the MC5 steel grade, the C is slightly increased, t...

AI Technical Summary

Problems solved by technology

Excessive reduction in the second pass of the roll body may cause transverse cracks and small openings in the roll body. When the roll neck is deformed, the temperature is between 800 and 900 ° C. The deformation rate of the roll neck is too large and the deformation temperature is too low to cause internal carbide segregation. zone cracking

The deformation temperature of the roll neck is high, the local deformation rate is large, and the deformation speed is fast, which may easily cause overheating cracks in the carbide segregation area inside the roll neck

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