Grooved Roll Friction Distribution for Pipe Polygonization

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Solution Overview

Problem

Conventional methods struggle to stably suppress polygonization in pipes with varying wall thickness and conditions, as existing techniques either fail to maintain consistent suppression or require complex adjustments to roll parameters and temperature control.

Innovation Solution

A grooved roll with a friction distribution in the roll axial direction, where the groove bottom zone has a higher frictional force than the flange zones, achieved through varying surface roughness or lubricity modifier application, to uniformly distribute wall thickness increases and prevent polygonization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional grooved rolls with uniform friction distribution are used, then the rolling process is simple to operate, but polygonization occurs due to non-uniform wall thickness distribution

Engineering Contradiction:

Improvewall thickness distribution uniformityVSAvoidroll surface structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The grooved roll surface is designed with different friction characteristics in different zones: the groove bottom zone has higher friction (rougher surface) while the flange zones have lower friction (smoother surface). This local differentiation of surface properties creates a friction distribution that promotes uniform wall thickness increase and suppresses polygonization, resolving the contradiction between manufacturing precision and device complexity.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If rectangularity of roll groove is adjusted to suppress polygonization, then manufacturing precision improves, but the adjustment process becomes more complex

Engineering Contradiction:

Improvepolygonization suppressionVSAvoidroll groove design complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of adjusting the geometric rectangularity of the groove, the invention changes the friction parameter of the roll surface through controlled roughness variations. By modifying the surface friction characteristic rather than the groove geometry, polygonization is suppressed while maintaining manufacturing simplicity, as the friction distribution can be achieved through standard surface treatment processes.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If multiple rolling stands with phase angle adjustments are used, then polygonization is reduced, but the operational complexity and number of components increase

Engineering Contradiction:

Improvepolygonization controlVSAvoidnumber of rolling stands

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the polygonization suppression function from the complex multi-stand system with phase angle adjustments and implements it directly in the grooved roll design. By incorporating the friction distribution directly into the roll, the need for multiple stands with coordinated phase angles is eliminated, reducing device complexity while maintaining manufacturing precision.

Inventive Principle:

Principle #2Taking out (Extraction)

4Manufacturing precision

If water cooling is applied to suppress polygonization, then manufacturing precision improves, but energy consumption and system complexity increase

Engineering Contradiction:

Improvepolygonization suppressionVSAvoidcooling energy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The invention converts the naturally occurring friction in the rolling process into a beneficial effect. By strategically distributing friction across the roll surface, the inherent friction force is used to promote uniform plastic deformation and suppress polygonization, eliminating the need for energy-consuming water cooling systems while maintaining manufacturing precision.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

This approach effectively minimizes and eliminates polygonization in pipes with different parameters by controlling the frictional forces along the groove surface, ensuring consistent wall thickness distribution and reducing polygonization across various conditions.

Implementation Method 1

the surface of the groove has a friction distribution in the roll axial direction such that the frictional force with respect to a material being rolled in the groove bottom zone is greater than the frictional force with respect to a material being rolled in the flange zones

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8276424B2Grooved roll for a reducer and a reducer

Publication Date: 2012.10.02 NIPPON STEEL CORPORATION

AI summary

A pipe in which polygonization is substantially eliminated is manufactured by a reducer with a grooved roll with a groove having a groove bottom zone including the center of the groove in the roll axial direction and flange zones adjoining both sides of the groove bottom zone. The groove surface has a friction distribution in the roll axial direction such that the frictional force with respect to a material being rolled in the groove bottom zone is larger than the frictional force with respect to a material being rolled in the flange zones. This friction distribution can be achieved by working the groove surface so that the surface roughness of the groove bottom zone becomes greater than the surface roughness of the flange zones or by applying a lubricity modifier which differs with respect to amount and/or type between the groove bottom zone and the flange zones.