Rolling quality control — keeping plate thickness uniform During plate rolling, what design feature is provided on the work rolls to compensate for elastic deflection and ensure uniform exit thickness across the width?

Introduction / Context:
When rolling wide plates, the work rolls elastically bend under separating force. If left uncorrected, the roll gap becomes wider at the edges than at the center, producing a crown or wedge in the strip. Roll camber is a classical corrective technique to achieve uniform thickness.

Given Data / Assumptions:

• Work rolls are subject to bending under load.
• Goal is uniform exit gauge across the width.
• No automatic roll-gap feedback control assumed.

Concept / Approach:
Camber means grinding the rolls with a slight convex profile so that, under load, elastic flattening produces an effectively straight generatrix. The pre-compensation is chosen based on expected rolling force and mill modulus. While hardening improves wear and bearings reduce friction, neither directly corrects roll bending. Backup rolls (in 4-high mills) and CVC or bending systems can also be used, but basic practice is to apply appropriate camber to work rolls.

Step-by-Step Solution:

Verification / Alternative check:
Mill setup sheets specify roll crown (camber) values; gauge maps confirm improved flatness and thickness after correct cambering.

Why Other Options Are Wrong:

• Offset: misalignment, not a thickness-control feature.
• Hardening: combats wear, not elastic deflection.
• Antifriction bearings: reduce power loss; do not shape the gap.
• Crowned backup rolls alone: helpful in 4-high mills but the direct answer for work rolls is camber.

Common Pitfalls:
Assuming flat-ground rolls yield flat plates under load; ignoring the mill modulus and force-thickness interaction.

Final Answer: