Roll defect management process
AssigneeDofasco Inc.
InventorsTed Kerr, Ron Webber, Ron Howard, William Hill
Life of this patent
Estimating the term…
Abstract
The Roll Defect Management Process (RDMP) is a system which is designed to manage, track and evaluate all mill rolls found in use in the hot and cold production of flat rolled metal strip. The RDMP is capable of detection, distinction and differentiation of various defects found in the mill roll using a nondestructive inspection system for generating variable amplitude output voltage signals corresponding to changes in physical properties found in a mill roll and defines corrective action for each roll type, mill, stand and position. The disposition and corrective actions of the RDMP are automated and dependent on the determination of various thresholds identified by roll, mill and stand.
Claims28
A method for inspecting a mill roll used for producing flat rolled metal strip and for disposition of a mill roll of predetermined type and in service on a predetermined mill stand as a function of any defects detected in said mill roll, the method comprising the steps of:
- a) applying a nondestructive inspection system to generate variable amplitude output voltage signals corresponding to changes in physical properties along a reference direction for at least a portion of the mill roll, any said changes in physical properties corresponding to a mill roll defect;
- b) defining an output voltage signal pattern from said variable amplitude output voltage signals;
- c) classifying said mill roll defect in accordance with predetermined patterns of output voltage signals;
- d) selecting a threshold signal value corresponding to said classified mill roll defect for the type of mill roll being inspected on said mill stand;
- e) calculating a difference between a maximum peak height for the output voltage signals and said threshold signal value;
- and
- f) defining corrective action for disposition of the mill roll in accordance with said calculated difference.
A method for inspecting a mill roll used for producing flat rolled metal strip and for disposition of a mill roll of predetermined type and in service on a predetermined mill stand as a function of any defects detected in said mill roll, the method comprising the steps of:
- a) applying an eddy current voltage to generate variable amplitude eddy current voltage signals corresponding to any changes in electrical conductivity along a reference direction for at least a portion of the mill roll, any said changes in electrical conductivity corresponding to a mill roll defect;
- b) defining an output voltage signal pattern from said variable amplitude eddy current voltage signals;
- c) classifying said mill roll defect in accordance with predetermined patterns of eddy current voltage signals;
- d) selecting a threshold signal value corresponding to said classified mill roll defect for the type of mill roll being inspected on said mill stand;
- e) calculating a difference between a maximum peak height for the eddy current voltage signals and said threshold signal value;
- and
- f) defining corrective action for disposition of the mill roll in accordance with said calculated difference.
A system for inspecting mill rolls used in the production of flat rolled metal strip and for defining corrective action for disposition of mill rolls, the system comprising:
- a) data input means for receiving data defining a roll history and mill history associated with a roll being inspected;
- b) a database of threshold signal values each corresponding to an acceptable output voltage signal for a roll having a predetermined roll history and mill history and having a predetermined type of mill roll defect;
- c) a non destructive inspection system for generating variable amplitude output voltage signals corresponding to changes in physical properties associated with mill roll defects;
- d) signal processing means for receiving said variable amplitude output voltage signals and defining a voltage signal pattern;
- e) signal classification means for classifying said voltage signal pattern in accordance with predetermined patterns of output voltage signals associated with predetermined types of mill roll defects each having a predetermined threshold signal value;
- f) computation means to calculate a difference in a maximum peak height for the output voltage signals characterizing said voltage signal pattern and said predetermined threshold signal value and to define corrective action for disposition of the mill roll;
- and
- g) transfer means for conveying information about said corrective action.
A graphical tabulation of threshold signal values each corresponding to an acceptable output voltage signal for a roll having a predetermined roll history and mill history and having a predetermined type of mill roll defect, the threshold signal values being displayed as a bar chart with the height of a bar associated with a first axis corresponding to output voltage signals generated by a nondestructive inspection system and a second axis corresponding to a depth of material to be removed from a mill roll.
A mill roll insert comprising a plate for mounting on a mill roll, the plate having defects formed therein for generating output voltage signals of predetermined amplitude to calibrate a nondestructive inspection system.
Dependencies are inferred from the claim text.