API Laser Tracker Used for a Rolling Mill Calibration

Handan Iron & Steel Group Used API’s Laser Tracker to Calibrate Their Rolling Mill


Handan Iron & Steel Group (Han Steel) was established in 1958 in Handan city, Hebei province, China.  With over 50 years of development, Han Steel has over 85.6 billion Yuan in total assets and 24,000 staffs.  Hans Steel is capable of producing up to 13,000,000 tons of steel annually and has become a staple for steel production in China.  To maintain quality control in the production process, Hans Steel relied on API’s expertise to make their rolling mill calibration more efficient and accurate .  API was able to provide quality solutions to update Han Steel’s calibration technology.


How Does a Rolling Mill Work?
When the steel ingots leave the smelt plant, they are then rolled by the rolling mill machines and the process is complete.  As shown in the picture below, the steel ingots will go through the rolling mill machine in the direction of the red arrow.  Meanwhile, the bearing “M” will provide and control the pressure.  The roller “A” and “B” roll simultaneously.  After 8 groups of the rolling mill machine, the steel ingots cling to the steel plate, cool down, and then become the finished product.

The Issue
Because the rollers are under constant stress, the position between the rollers and the roller housing may deviate after long periods of use. This will trigger the change in shape of the steel plate. For example, one side may become higher and the other side lower. Over time, the roller’s surface will lose its flatness, thus making the steel plates produced uneven and bringing cause for the rolling mill calibration.

The API Solution
API suggested Han Steel use its Radian laser tracker, combined with the necessary software, to resolve the problem.  The API Radian laser tracker recorded multiple reference points on both the roller and roller housing. These reference points were then used to create a standard position relationship between the roller and roller housing.  API’s software was used to analyze the standard position relationship to figure out the value that required adjustment.  This value was key in guiding Han Steel’s engineers in adjusting the roller’s position. To resolve the roller’s surface flatness problem, the Radian laser tracker collected several reference points on the surface of the roller.  These reference points were used collectively to make a standard cylinder in the software.  The corresponding actual value was then compared with the standard value to determine what exactly needed to be fixed or maintained.

Stability in Harsh Environments
As shown with Han Steel, the API Radian laser tracker has the ability to adapt to harsh working environments. During the processing of steel, water is poured on the hot steels to cool it down. As a result, large amounts of steam is produced inside the plant. Unlike other precision measuring equipment, the Radian Tracker’s versatility allows it to work under the humidity environment 0-100% (no condensing). API-Laser-Tracker-is-stable-in-harsh-environments-300x232Weather stations also take advantage of this versatility and use the Radian to perform an important role. The sensors on the weather station detect the environment in real-time, and give feedback to the Radian to compensate the values in real-time which makes calibrating the rolling mill possible.

About API 
Automated Precision Inc. is a world leader of advanced metrology solutions for industry. Founded by Dr . Kam Lau in 1987, API has pioneered progressively higher standards of accuracy for coordinate measuring and machine tool operation. API products are installed and used by all of the world’s leading automotive, aerospace, machine tool, and CMM manufacturers.