Wet Temper Rolling Tension Control to Prevent Steel Sheet Jumping

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Solution Overview

Problem

Existing methods for preventing jumping in wet temper rolling, such as adjusting temper rolling liquid concentration and combining wet and dry temper rolling, are either ineffective in reliably preventing surface roughness changes or not applicable to single-stand rolling mills.

Innovation Solution

A method for setting tension in wet temper rolling based on the carbon content, sheet thickness, load, and surface roughness of the work rolls, using a specific formula to determine optimal tension ranges that prevent jumping and cross buckling, applicable to both single-stand and multi-stand rolling mills.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the concentration of temper rolling liquid is adjusted to prevent jumping, then the occurrence of jumping is reduced, but the surface roughness and appearance of the steel sheet change

Engineering Contradiction:
Improveprevention of jumpingVSAvoidsurface roughness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the parameter being adjusted from temper rolling liquid concentration to tension force applied to the steel sheet. By controlling tension within a specific range (5-15 kgf/mm²), the method prevents jumping while maintaining stable surface roughness, as tension directly affects elongation ratio without altering the liquid concentration that would otherwise change surface properties

Inventive Principle:
Principle #35Parameter changes

2Reliability

If wet temper rolling and dry temper rolling are used in combination to prevent jumping, then jumping is prevented, but the method becomes inapplicable to single-stand rolling mills

Engineering Contradiction:
Improveprevention of jumpingVSAvoidapplicability to rolling mill configurations
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention creates a universal solution by developing a tension-based control method that can be applied to any rolling mill configuration, whether single-stand or multi-stand. The method uses a unified tension range (5-15 kgf/mm²) that works across different rolling mill types, eliminating the need for configuration-specific processes

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If tension is increased to control elongation ratio, then material properties are adjusted, but jumping occurs when tension is excessively high

Engineering Contradiction:
Improveelongation ratioVSAvoidstability of elongation
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention applies preliminary anti-action by establishing an upper limit for tension (15 kgf/mm²) before jumping can occur. By pre-defining this critical threshold and maintaining tension below it, the method prevents the harmful effect of jumping while still achieving the desired elongation ratio for material property adjustment

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP4094854B1Temper rolling method for cold-rolled steel sheet
Publication Date: 2024.05.29 JFE STEEL CORP
  • EP4094854B1 patent drawingFigure 1

AI summary

The present invention provides a method for performing temper rolling on a cold rolled steel sheet, the method being designed to prevent the occurrence of problems such as jumping; the method relates to wet temper rolling and addresses changes in a concentration of a temper rolling liquid and changes in a load, and the method is applicable to both a rolling mill with a single stand and a rolling mill with multiple stands. A method for performing temper rolling on a cold rolled steel sheet, the temper rolling including wet temper rolling, the cold rolled steel sheet being an annealed cold rolled steel sheet, the method including setting a tension T (kgf/mm2) per unit cross-sectional area of the steel sheet for the temper rolling, based on a carbon content C (mass%) of the cold rolled steel sheet.