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Why should alloy cast steel rollers undergo spheroidization and annealing heat treatment?

Why should alloy cast steel rollers undergo spheroidization and annealing heat treatment?

The spheroidizing and annealing heat treatment of alloy cast steel rollers is mainly aimed at improving the cutting performance of the rollers, improving cutting efficiency, and preparing the corresponding microstructure for subsequent quenching treatment. Spheroidizing annealing treatment causes the carbides in the structure to transform from flake to spherical, which means that spherical or granular carbides are uniformly distributed on the matrix of ferrite, forming a spherical pearlite structure. The spheroidization temperature selected in production is generally slightly higher than the critical point of Ac1. If the temperature is too low, the required spheroidization time is too long, while if the temperature is too high, it will lead to the appearance of granular pearlite with varying particle sizes.

Why do alloy cast steel rollers undergo quenching heat treatment?

Why do alloy cast steel rollers undergo quenching heat treatment?

Quenching of alloy cast steel rolls is a heat treatment process in which the roll is heated to a critical temperature (Acm or Ac1), held for a relative time to fully austenitize, and then rapidly cooled to the bainite transformation zone at a cooling rate greater than the critical cooling rate, thereby obtaining the bainite structure in the working layer of the roll body.

What should be paid attention to when classifying and selecting rollers

What should be paid attention to when classifying and selecting rollers

The main working components and tools on a rolling mill that cause continuous plastic deformation of metal. The rolling roller mainly consists of three parts: the roller body, the roller neck, and the shaft head. The roll body is the middle part of the roll that actually participates in rolling metal. It has a smooth cylindrical or grooved surface. The roller neck is installed in the bearing and transmits the rolling force to the frame through the bearing seat and pressing device. The transmission end shaft head is connected to the gear seat through a connecting shaft, transmitting the rotational torque of the motor to the rolling roller. The rolls can be arranged in the form of two, three, four, or multiple rolls in the rolling mill frame.

Life and Flaw Detection Standards of Cold Rolling Rolls

Life and Flaw Detection Standards of Cold Rolling Rolls

The main steps in the manufacturing process of cold rolling rolls include melting, forging, heat treatment, processing, and inspection. During the working process, cold rolling rolls must withstand significant rolling stress. In addition, problems such as weld seams, inclusions, and edge cracks in the rolled parts can easily lead to instantaneous high temperatures, causing strong thermal shock to the working rolls, causing cracks, sticking, peeling, and even scrapping. Therefore, cold rolling rolls should have the ability to resist cracking and peeling caused by bending stress, torsional stress, and shear stress, as well as high wear resistance, high contact fatigue strength, high fracture toughness, and thermal impact strength.

How to prevent the harm of rollers and improve work efficiency?

How to prevent the harm of rollers and improve work efficiency?

The working conditions of the rollers in the rolling mill components are relatively chaotic. Residual stress and thermal stress may occur during the preparation process before production and use of the roller. During application, it is further subjected to various cyclic stresses, including twists and turns, modifications, shear forces, contact stresses, and thermal stresses. The distribution of these stresses along the roll body is uneven and constantly changing, not only due to planning elements, but also to the continuous changes in wear, temperature, and roll shape during the use of the roll. In addition, rolling conditions often exhibit abnormal conditions. Improper cooling of the roller after use can also cause harm from thermal stress. So in addition to wear and tear, the rollers often exhibit various damages such as cracks, cracking, detachment, and indentation, as well as external damage.

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