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No matter what´s on your Plate – Shapeline knows
Plates are getting wider, harder and thinner. These features give flatness ever increasing importance, and a good flatness measurement will not only make a speedy return on investment, it will soon become a standard requirement.
However, to measure flatness on plates is in itself a challenge. Waviness in combination with rolls, introduces shape changes that have to be eliminated in hardware and software before an evaluation can be made. When this is mastered, there are great benefits in quenching improvement as well as leveller control and efficiency.
The Shapeline Plate software eliminates all these problems once a minor modification has been made to the production line. Shapeline has had experience in topographic plate measurements using laser line projection for eight years. The measurement results are accurate and of great assistance to operators and process development personnel. This is also evident in the benefits experienced.
• Faster start-up of new levellers and quenching equipment => faster time-to-market.
• Improvement of existing processes and faster decisions eliminate bottlenecks => More plates per hour.
• Better control of plate flatness => Higher and documented quality and higher yield.
Plate rolling
Modern plate production requires thinner and thinner plates. This places high demands on the rolling process in terms of on-line measurement.
A Shapeline system can measure the plate shape during the rolling process for fast feedback to the operator, who can then use the information in combination with thickness, and change roll bending accordingly. Since the technology also reports (flatness compensated) width and centreline data, the tool is even more advantageous.
To go one step further, different measurements can also be integrated into a common C-frame where thickness, temperature profile and speed are measured. A Shapeline system is mounted inside or onto the C-frame to measure material vertical position, surface slope and unflatness in the same line as the thickness measurement. The thickness measurement data can then be adjusted based on these measurements.
Plate quenching
Plate quenching lines are becoming increasingly common as a result of increased market demand for harder and stronger steel plates. What every plate producer knows is that during the quenching process the plate undergoes a transformation from an austenitic into a martensitic structure.
If this process is irregular, the shape of the plate is affected. One way to minimize this irregularity is to fine tune the quenching process.
Since the unflatness reflects the irregularities in the quenching process, a good flatness measurement is of great assistance in the tuning process. Shapeline can not only provide this, it can also provide tools for finding systematic irregularities in the flatness and also in the quenching process.
Plate levelling
Plates are levelled to change the internal steel structure as well as to improve the plate flatness. Levelling is a complex process since only a part of the cross section is affected, and different dimensions as well as steel grades and incoming unflatness require different leveller settings. The task for the operator is therefore complex and a good leveller operator requires years of training and experience.
A Shapeline system installed on the exit side of the leveller simplifies this task dramatically. The measurement delivers an objective view of the flatness, calculates parameters (e.g. I-units) that are easily understandable and correspond to the function of the leveller. It is even possible to make the levelling automatic.
Experience has shown that it is possible to reduce the number of levelling passes to just one in normal circumstances, also for thin and hard plates after systematic improvement work using a Shapeline system. This saves time and decreases the dependency on the operators
Quality assurance
Plate producers are obliged to check every plate to certify that the material has the right flatness according to the used norms. Different norms may apply for different end-users and in reality, the flatness requirements differ depending on how the steel plates are used. It is therefore necessary to have a discussion with the user.
In these discussions, topographical pictures of the plates can be of great help. A Shapeline system will check every plate according to the defined norms, store measurement data in a traceable way, and present measurement results in the way they are wanted.
Since this is done during normal plate transportation, no extra space or time is required. This is very valuable when designing new lines.
Measurement data may be condensed to long- and short-term statistics, useful for the continuous improvement process and process development.
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