Product Usage Guide
It is extremely important to use and maintain the rolls correctly in order to improve the service life and reduce costs incurred by constant replacement of the rolls.

Instructions for Production of Welded Tubes and Cold Rolled Section Steel
1. Inspection and acceptance of rolls:
1) Measure the bottom diameter, outer diameter, bore diameter and width of rolls.
2) Examine the inner bores by comparing their size to what is indicated by the corresponding template.
3) Examine the surface roughness.
4) Examine the concentricity between the inner and outer circles.
5) Ensure the appearance is intact.
6) Measure the hardness of the rolls using a hardness gauge.
7) Check to be sure the labels on the rolls are complete.

2. Clarify the rolls in terms of specifications, then put them on the shelves in order.

3. Create files and accounts for the rolls.
1) File Card: A specific number series is created and inscribed for each new roll that passes our examinations. The file card corresponds with each number series, and includes a list of specific information: the number series, steel grade, specification, shelf number, figure number, bottom diameter, weight, date when placed in the warehouse, start date for working time, replacement date, yield, coping date, bottom diameter after coping, scrapping date, and the reason for scrapping.
2) Accounts: Accounts are created to record information about stored rolls, working rolls, and rolls that have undergone the grinding process. Information of stored rolls consists of roll specification, sequence number for which shelf the roll is mounted on, and the number series of rolls that needs to be written down for on-line rolls and rolls undergoing grinding.

4. Coping of old rolls and template management
1) Templates should be placed into exclusive cabinets by specification and usage frequency in order to prevent confusion.
2) Templates should be validated periodically, and unqualified ones thrown out.
3) Old design drawings and templates should be discarded once the design of the inner bore has been altered.
4) Users should take care when using templates in order to prevent damage, and put them right back after usage to prevent damage or loss.

5. Prepare to replace rolls and select appropriate rolls
1) Prepare a full set of rolls and select those that are appropriate. The bottom diameter of the rolls on the self should progressively increase by 1mm. In addition, the diameter of the upper roll should be matched by the speed ratio with the bottom diameter of the corresponding lower roll.
2) Check the rolls to determine if they are qualified or not. Unqualified ones should not be used.
3) Arrange the matched rolls in order on the production file.
4) Wipe out rolls.

6. Rolls should be used in moderation. Users should make the most use possible of a roll before scrapping it.

7. Cleaning and maintenance
1) Rolls should be coated in a rust preventative oil after cleaning.

8. Roll Scrapping
1) Check is there is any damage to the roll using a visual or a template. If it can be repaired for future use, repair it. If not, discard it.

9. Roll Consumption
1) Calculate the roll consumption based on the amount of steel rolled.
2) Formula: roll consumption = total weight of rolls used/total weight of qualified products obtained (kg/T)

Cold rolls come in different types, including working rolls, backup rolls, intermediate rolls and leveling rolls. Here at Jiangsu Hero Way, our cold rolls are known for their ability to work even in harsh environments. With a high rolling speed and great rolling force, they are capable of bearing a static load and a dynamic load. Generally, the surface of the cold rolls will constantly rub with the surface of rolled metal, causing severe abrasion to the cold rolls. Because of that, the hardness of the surface on the cold rolls should be large, uniform, and feature a deep hardening layer. These rolls should also be designed with a great abrasion resistance and a high crack resistance.

1. New and fixed rolls need to be idle for a length of time in order to naturally relieve internal stress. Internal stress can also be removed using quenching oil of 80 to 120°C.
2. In Winter, or countries with high latitudes, cold rolls need to be preheated to 60-80°C before they are installed on the relevant machinery. Water cooling should stop immediately when the machine shuts down. When removed from the machine, the cold rolls should be placed on the self.
3. Cold rolls stored in the warehouse must go through a stress relief treatment at a temperature of 80 to 120° at the beginning of the spring season to prevent damage caused by sudden climate changes.
4. The roll barrel and roll neck need to be cooled and lubricated properly to prevent overheating during operation, as heat stress will cause microcracks or peeling on the roll barrel surface and rupture the roll neck.
5. Grinding wheels with the appropriate granularity and hardness should be used to prevent burning of the roll barrel during grinding. The amount of feed should not be equal to or greater than 0.025mm. In addition, the amount of cooling water used during the grinding process should be frequently adjusted.
6. Cold rolls with a different diameter, hardness and thickness are suitable for different working modes. The roll barrel is generally designed with a degree of convexity and surface roughness.
7. Cold rolls need to be ground every time they are put into operation in order to remove surface fatigue. Generally, the depth of the fatigue surface is about 0.08 to 0.1mm. That depth will vary in special service circumstances however.
8. Jamming of the steel during the roll process is not allowed. The welding joints on strip steel should be ground to ensure the smooth surface, which also prevents the roll surface from becoming damaged. There are times when the rolls crack or peel due to slight damage caused by the grinding and fatigue surface generated after long term use. Reasonable remedial actions should be taken periodically in order to prevent this from happening.
9. New rolls are suitable for the rolling of wide, thin and fine steel. With an increase in usage and repair times, the hardness and diameter of the roll will significantly decrease. As a result, old rolls can only be used to roll thick, narrow and coarse steel.
10. Rolling should be stable. Users are not allowed to adjust the voltage during downtime or idle run. They also should not frequently adjust the voltage unidirectonally, in order to prevent the roll neck from breaking at a 45 degree angle.
11. The rolled material should be clean. The roll barrel length should be matched with the width of the rolled strip. Backup rolls need to be smooth and clean, and must be periodically repaired as needed.