Patent pending.

During operation in the mill stand, the surface of a roll is exposed to high loads. This can create a damaged and work-hardened surface layer which must be removed completely before the roll is returned to service. At the same time, the removal of sound base material should be kept to a minimum in order to reduce diameter loss and extend roll life.

The required stock removal cannot be determined reliably in advance. The thickness of the work-hardened layer depends on many factors, including roll material, operating conditions, rolling campaign, roll condition and previous grinding history. In practice, this often results in conservative removal allowances. Although these allowances help ensure complete removal of the damaged layer, they can also cause unnecessary stock removal.

The Roll Works Roll Hardening Detector identifies the transition from the work-hardened surface layer to sound base material directly during the grinding cycle. It uses the process data available from the grinding machine and continuously compares the actual grinding behavior with a dedicated model for removing the work-hardened layer. As long as the measured behavior matches the behavior expected in hardened material, grinding continues. Once a significant deviation is detected, the system indicates that base material has been reached and the grinding cycle can be stopped.

Instead of relying solely on a fixed removal allowance, the required removal is detected within the individual grinding process. This enables complete removal of the damaged layer while avoiding unnecessary removal of sound roll material.

Technical notes

The Roll Hardening Detector is an optional add-on module for the Roll Works Optimizer. It uses the Optimizer’s AI component and the existing Roll Works data foundation. While the Optimizer models general grinding-machine behavior, the Detector extends this capability with dedicated detection of the grinding behavior associated with the work-hardened surface layer.

Depending on the available machine interface and the respective grinding process, the system
can consider data such as:

• Grinding current or grinding-wheel drive power
• Cutting speed
• Roll speed
• Infeed
• Roll parameters, including material and diameter
• Grinding-wheel parameters, including material, diameter and width

The system operates inline during the grinding cycle and does not require a separate hardness measurement during grinding. It is intended as an extension for Roll Works installations where the required process data are available through the Roll Works communication Interface.

Benefits

• Reduced unnecessary stock removal
• Lower roll diameter loss
• Longer usable roll life and more rolling campaigns per roll
• Shorter grinding cycles through lower safety allowances
• Reliable removal of the damaged and work-hardened layer
• No additional hardness-measurement equipment or measurement-related process
• interruptions
• Modular extension for Roll Works Optimizer