Skin-Pass Roll Surface Structure for Wettability and Retention

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Solution Overview

Problem

Existing steel sheet tempering technologies face challenges in achieving optimal wettability and retention capacity, with open structures offering good wettability but poor retention, and closed structures providing good retention but poor wettability, leading to inefficiencies in the tempering process and reduced service life of tempering rollers.

Innovation Solution

A semi-open surface structure on the steel sheet or a semi-closed structure on the tempering roll is designed, with specific dimensions and ratios of depressions to elevations, allowing for enhanced wettability and retention properties, achieved through precise control of laser texturing or other surface modification processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If an open surface structure is used on the steel sheet, then wettability is improved, but retention capacity deteriorates

Engineering Contradiction:
ImprovewettabilityVSAvoidretention capacity
Core Design Contradiction:
Difficulty of detecting and measuringVSQuantity of substance

Solution Approach 1:

The surface structure is designed with local variations in depression depth and connectivity. Some depressions are open to the surface while others are closed or semi-closed, creating different local zones with different functions: open zones for wettability and closed zones for retention capacity. This local differentiation resolves the contradiction between overall wettability and retention capacity.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If a closed surface structure is used on the steel sheet, then retention capacity is improved, but wettability deteriorates

Engineering Contradiction:
Improveretention capacityVSAvoidwettability
Core Design Contradiction:
Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The surface structure is segmented into multiple types of depressions: completely open depressions, semi-open depressions, and closed depressions. Each segment serves a different function in the tempering process. The segmentation allows the surface to simultaneously provide pathways for tempering agent distribution (open segments) and retention zones (closed segments), resolving the contradiction between wettability and retention capacity.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If skin-pass forces are applied to imprint structure, then structure depth is improved, but skin-pass agent distribution deteriorates

Engineering Contradiction:
Improvestructure depthVSAvoidskin-pass agent distribution
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The surface structure is pre-designed with channels and open depressions that facilitate the preliminary distribution of skin-pass agent before the imprinting force is applied. This preliminary action ensures that the agent is already positioned and distributed appropriately when the skin-pass roll applies force, preventing agent entrapment and ensuring uniform distribution even as deep structures are imprinted.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The semi-open or semi-closed surface structures enable effective distribution of tempering agents, improved force transmission, and deeper embossing of structures into the steel sheet, while maintaining a balance between wettability and retention capacity, thus enhancing the economic efficiency and performance of the tempering process.

Implementation Method 1

Laser texturing processes are preferably used to be able to adjust targeted structures (positive shape) on the surface of a skin-passing roll by removing material

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4182099B1Skin pass rolled sheet steel, skin pass roll and method for producing skin pass rolled sheet steel
Publication Date: 2024.05.29 THYSSENKRUPP STEEL EUROPE AG PATENTE PATENT DEPARTMENT
  • EP4182099B1 patent drawingFigure 1a)~1g)

AI summary

The invention relates to sheet steel that has been provided with a surface structure by skin pass rolling, a skin pass roll structured with a surface structure and a method for producing skin pass rolled sheet steel.