The following is a brief talkRollerMaintenance and production standards

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Maintenance and management of rigid roll

1. Correctly judge the number of uses. The grinding interval of high-speed steel rolls depends on the oxide film on the surface of the roll and the maintenance of roughness after each shutdown. Under normal circumstances, the front frame can be used 3~7 times, and the rear frame can be used 2~4 times, and the high-speed steel roll can even be used more than 10 times.

2, through the roll surface flaw detection to avoid roll failure, high-speed steel roll should be immediately water cooling or air cooling, to ensure that before the next use to eliminate thermal expansion, high-speed steel roll is prone to thermal cracks, if abnormal shutdown, should immediately replace the high-speed steel roll, in order to avoid roll spalling and other failure accidents, should use ultrasonic flaw detector to detect the cooled roll surface cracks.

3. Use professional tools to strengthen the grinding effect. Due to the high hardness of high-speed steel rolls and the difficulty of grinding, special grinding wheels and automatic grinding machines should be used. After grinding, eddy current flaw detector and ultrasonic flaw detector should be used to detect the surface of the rolls. After grinding, the high-speed steel rolls of ordinary machine tools can retain micro-thermal cracks for use on machine tools, but for high-speed steel rolls that are tripped in rolling accidents, on the basis of grinding, a certain amount of grinding should be added to remove the cracks on the surface of the roll.

Standards for the production of rolls

The roll is an important part of the rolling mill in the rolling mill, which uses a pair or a groupRollerThe pressure generated is used to roll and grind the steel. It mainly bears the influence of dynamic and static load, wear and temperature changes in the rolling process. The roll paper produced and processed is made of iron, and has professional quality assurance. Because of professionalism, So they are very good.

Commonly used cold.RollerThere are 9Cr, 9Cr2, 9Crv, 8CrMoV, etc. Cold rolls require surface quenching with hardness of HS45 ~ 105. Commonly used hot roll materials are 55Mn2, 55Cr, 60CrMnMo, 60SiMnMo, etc. Hot rolling is used for billet opening, thick plate, section steel and other processing. It bears the influence of large rolling force, serious wear and thermal fatigue. Hot rolls have high working temperature and allowable surface wear diameter per unit workload, so on, only high strength, toughness and heat resistance are required.

The hot roll only adopts integral normalizing or quenching, and the surface hardness requires HB190 ~ 270 hardness. The roll hardness is an indirect physical quantity, and its level is affected by the internal tissue state of the roll itself, such as the matrix hardness of the roll material, the type and quantity of carbide in the roll material, the residual stress of the roll, etc. At the same time, the Shore hardness test and the Richter hardness test commonly used in the roll hardness test are rebound hardness test, it is greatly affected by other factors such as the state of the testing instrument and the psychological factors of the operator.

Therefore, whether it is the manufacturing and use department of the roll, it is necessary to designate a special person to be responsible for hardness testing, pay attention to the selection of the hardness tester, maintain a stable comparison with other hardness, and pay attention to the regular inspection and calibration of the hardness testing instruments and standard test blocks. Conditional enterprises can promote the use of standard rollers for hardness tester calibration.

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