Ontology of the Steel Industry Case Study
action
This is the final assignment of a coil to an order (a customer)
derives from
A given phenomenon derives from a set of defects.
has phenomenon
has sampling point
in coil
This property links sampling points, used by the system to measure some physical parameters such as the yield strength, to the product (a given coil).
location
A defect is detected comparing coil data with order specifications in sampling points. Thus a defect is relative to a position in the coil.
location of
order
This is the initial assignment of a coil to an order (a customer). It will define the production goal to be validated by the rule system.
phenomenon of
steel grade
top object property
average flattener elongation
average skin-pass elongation
average temperature
coil identifier
coil property
flattener elongation
length scope
Length of the coil in which the sampling applies. It is associated to a single coil sampling point.
position
Position of the coil where a sampling is performed. There is a sampling point each 10 meters from the head to the tail of the coil, so the position indicates the distance in meters from the head to a given sampling point.
product type code
sampling point property
skin-pass elongation
skin-pass elongation maximum
skin-pass elongation minimum
target parameter
temperature
temperature maximum
temperature minimum
thickness target
weight maximum
weight minimum
width target
yield strength
This parameter is calculated in every sampling point along the coil. So the yieldStrength is associated with a given sampling point to allow the comparison with the yieldStrength value of the target specified in the order. Deviations from the target imply a defect in the coil.
yield strength upper tolerance
yield strength lower tolerance
zinc thickness target
top data property
Action
This category comprises the actions to be done with the product after the system has completed its evaluation
Clinching
Clinching steels are those obtained by a non-continuous method of joining whereby the points of joinage are produced by punching two or more steel sheets together simultaneously by means of a punch and die.
Coil
A coil is a physical object which is the metallurgical product to be analysed during the process.
An imperfection or defect detected in the coil.
Defect
Dual-phase steel
Dual-phase steel (DPA) is a high-strength steel that has a ferrite and martensitic microstructure. DPA starts as a low or medium carbon steel and is quenched from a temperature above A1 but below A3 on a continuous cooling transformation diagram. This results in a microstructure consisting of a soft ferrite matrix containing islands of martensite as the secondary phase (martensite increases the tensile strength). It features advantages such as low yield strength;low yield to tensile strength ratio (yield strength / tensile strength = 0.5); high initial strain hardening rates; good uniform elongation; high strain rate sensitivity (the faster it is crushed the more energy it absorbs); and good fatigue resistance.
High-strength low-alloy steel
High-strength low-alloy (HSLA) steel is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. HSLA steels vary from other steels in that they aren't made to meet a specific chemical composition, but rather to specific mechanical properties. They have a carbon content between 0.05?0.25% to retain formability and weldability.
Intertitial free metallurgy steel
Steels designed to provide an excellent combination of drawability and mechanical strength based on their specific interstitial free (IF) metallurgy. These steels are hardened by adding manganese, silicon and phosphorous in solid solution to the ferrite. The metallurgy of IF steels optimizes their drawability.
Mechanical defect
A defect having to do with the mechanical process.
Mechanical phenomenon
An effect detected in the coil related to the mechanical process.
Order
An order defines the target specifications of the product. The order also specifies the tolerance allowed with respect to the target parameters.
Parameter defect
It is a defect having to do with a deviation of the measured skin-pass elongation, flattener elongation or temperature from the specified values.
Phenomenon
An effect detected in the coil, based on the identified defects along the coil sampling points.
Product type
The type identifies the kind of steel, defined by a set of physical and chemical properties
Rephosphorised steel
It is a kind of steel that contains phosphorus as its main alloying agent.
Sampling point
A sampling point is an abstract concept which represents a given location within a coil where some physical parameters are measured.
Skin-pass elongation defect
A skin-pass elongation defect has to do with any deviation of the measured skin-pass elongation from the requirements for the product.
Skin-pass elongation phenomenon
An effect detected in the coil related to the skin-pass elongation.
Surface aspect defect
A defect found in the surface of the coil.
Surface aspect phenomenon
An effect detected in the coil specifically on the surface of the product.
Temperature defect
It is a defect having to do with temperature issues. At the exit of the furnace it is necessary to check the temperature ranges of the steel strip, depending on the maximum and minimum end of heating temperature set by the order (measured in �C) and the steel grade.
Temperature phenomenon
An effect detected in the coil related to the temperature.
Yield strength defect
It is a mechanical defect having to do with the target yield strength. A defect of this category is identified if the yield strength is outside of the target range at any point.
Yield strength phenomenon
An effect detected in the coil related to the yield strength.
evaluation
The coil is sent to experts when it is not clear whether it meets order requirements
Keep assignment
repair
When the quality of coil is low but it could be repaired, it is sent again to the production line.
scrap
When the quality of the coil is very low, it is sent to scrap