WO2019073398A1

WO2019073398A1 - System and method for metals' heat treatment quality control

Info

Publication number: WO2019073398A1
Application number: PCT/IB2018/057839
Authority: WO
Inventors: António Paulo CERQUEIRA DUARTE
Original assignee: Metalsolvus Unipessoal Lda
Current assignee: Metalsolvus Unipessoal Lda
Priority date: 2017-10-10
Filing date: 2018-10-10
Publication date: 2019-04-18
Anticipated expiration: 2020-04-10

Abstract

La présente invention porte sur un système qui résulte de la nécessité de gérer de manière rapide, fiable et efficace la conformité dans des cycles de traitement thermique de métaux, par exemple des aciers, en évaluant la qualité de procédés thermiques et en développant des actions d'amélioration afin de valider la conformité du cycle réalisé et du produit transformé. Le système comprend un four (1), des thermocouples connectés à la console, et un automate IHM (interface homme-machine) et un PLC (contrôleur programmable) (2) qui donnent et enregistrent des informations dans la base de données (3) en ligne avec le programme d'ordinateur (4) chargé d'établir des rapports dans différents formats (5). Le procédé de la présente invention consiste à recueillir, stocker et traiter des données de façon à préparer des rapports de traitement thermique de métaux. Un traitement thermique met en œuvre le système et le procédé permettant, simultanément, de garantir l'efficacité de procédé, d'équipement et de produit, en présentant et en vérifiant des informations ainsi qu'en effectuant automatiquement les modifications nécessaires.The present invention relates to a system that results from the need to rapidly, reliably and effectively manage compliance in heat treatment cycles of metals, for example steels, by evaluating the quality of thermal processes and by developing actions of improvement in order to validate the conformity of the realized cycle and the transformed product. The system includes an oven (1), thermocouples connected to the console, and an HMI (human-machine interface) and a PLC (programmable controller) (2) which give and record information in the database (3) in line with the computer program (4) responsible for reporting in different formats (5). The method of the present invention includes collecting, storing and processing data to prepare metal heat treatment reports. Heat treatment implements the system and method that simultaneously ensures process, equipment and product efficiency by presenting and verifying information as well as automatically making the necessary changes.

Description

DESCRIPTION

"SYSTEM AND METHOD FOR METALS' HEAT TREATMENT QUALITY

CONTROL"

Technical field

This application involves a device and the managing method in quality control of metals' heat treatment process.

State of the art

The process of metals' heat treatment, e.g. steels, is carried out in electric or gas furnaces, controlled by using temperature probes/sensors, (typically thermocouples) which, by monitoring the temperature inside the furnace enable the current intensity to be controlled (electric furnaces) as well as the combustion (gas furnaces) thus ensuring that the most convenient temperature is used at each moment of the heat treatment cycle applied by the furnace on the parts.

The heat treatment process is ensured in terms of quality both by the measurement of the characteristics applied to the parts through making physical tests, and by analysing of temperature variation records according to time, usually known as heat treatment graphs. These graphs normally represent in the yy axis, the temperature values given by the furnace thermocouples and in the xx axis, the time in relation to each temperature record.

Nowadays, furnaces have temperature information recording systems regarding time enabling these data to be shown on paper, pdf file or directly on screen. The heat treatment graphs thus obtained allow the process main parameters achieved to be viewed for subsequent compliance validation of the cycle carried out as well as the product thereby transformed.

The solution of thermal processes temperature data collection is made by using equipment such as dataloggers that allow information output to Excel files or specific programs for treating acquired data.

The Datapaq US 4,817,049 document describes a device for signal collection based on a datalogger with data storage internal memory. This type of solution is based on the use of microprocessors, especially used to control heat treatment cycles in a mobile manner, such as painting cabins or continuous furnaces, where the cycle monitoring not possible in any other way and the process control is ensured by fixed position thermocouples placed inside that thermal equipment that measure constant temperatures and not depending on the process cycle. These devices are placed inside insulated or internally refrigerated boxes, to which thermocouples are connected and data record takes place on the device, as it moves inside the furnace, as shown on document EP1202014A2. This type of device, however, does not allow the input and association of enough data regarding production identification, due to the simplicity of the solution used and insufficient graphic interface and data processing on which this type of solution is based. For data analysis resulting from this solution, software is used, from the device supplier itself, that process the obtained information based on temperature diffusion monitoring inside the furnaces, its analysis being based on the ease of obtained graph magnification and simple temperature observation. Existing solutions from Grant and Datapaq companies do not allow thermal treatment cycle analysis on a routine basis, but only particular studies, or the monitoring of the furnace's condition in terms of temperature diffusion, not even including in this case the automated analysis, thus requiring a long period of analysis.

Solutions based on devices such as dataloggers, as described by document US20140118957A1 from Yokogawa Electric Corporation with internal or networked storage, enable the recording of data on databases for later interpretation by the user based on data export to spread sheets, paper printing or data treatment customized solutions, although these solutions do not solve the problem that is overcome with this invention, since data input for material, equipment and operator identification is conditioned and data automatic treatment does not exist, along with the preparation of thermal treatment reports being poor.

This invention enables data collection, information storage and subsequent software processing to allow for automatic calculation of the main process variables and later report production as well as automatic validation of the heat treatment cycles carried out.

Summary

This application describes a system for quality control of metals' heat treatment, implemented by computer and including :

- furnace, console and automaton - HMI (Human-Machine Interface) panel interface and PLC (Programmable Logic Controller) ,

- database,

- computer program issuing reports in various formats.

In an embodiment the system comprises thermocouple entries and indicators; functioning, alarm and record.

In another embodiment the system on the panel side, including console and automaton - HMI and PLC collects data (temperature and time) of the thermal treatment from the furnace .

Still, in another embodiment the system on the panel side including console and automaton - HMI and PLC collects additional data input by the operator.

In another preferred embodiment the system includes network connection .

In another embodiment the system is characterized by data being stored in computer databases.

In an embodiment the system is characterized by the data analysis being done by using a computer program.

In another embodiment the system is characterized by the issuing of the quality control reports being done in the following formats: doc, pdf, csv or other for being read by additional software, such as, among others, word, excel, which are exported by the dedicated software or by direct paper printing.

Again, in another embodiment the system is characterized by HMI and PLC being included in an electrical cabinet. This application also describes the method that operates the system as described in the previous paragraphs.

This application describes the method characterized by comprising the following steps:

- production data input,

- data collection,

- information storage,

- data analysis by dedicated software,

- report production, issuing and storage.

In another embodiment the method is characterized by the data collection step being done through the information received from the furnace thermocouples and data collection from each production lot/batch.

In another embodiment the method is characterized by the information being added to data supplied by an external source by the operator or by the software.

Still, in another embodiment the method is characterized by the information storage step being done by using any platform in windows Environment.

In another preferred embodiment the method is characterized by the information storage step including an encrypted database .

In another embodiment the method is characterized by the storage step working in local server or in cloud computing.

In another embodiment the method is characterized by the data analysis in the software simultaneously carrying out data acquisition and making available different analysis from data base consulting.

In another embodiment the method is characterized by the distinct analysis being:

- hardening cycles,

- stress relief and tempering cycles,

- furnace temperature dispersions monitoring.

In another embodiment the method is characterized by the reports produced by the program being exported for printing and storage in various formats, such as pdf, word, excel, among others and being stored again in the local server or in the cloud.

In another embodiment the method is characterized by the data input by the operator providing the following elements related to the furnace collection:

- Equipment identification,

- operator identification,

- lot/batch identification.

In another embodiment the method is characterized by the operator' s data input providing the following elements associated to the furnace collection:

Load placed inside the furnace - weight (under treatment) .

In another embodiment the method is characterized by the collected temperature data being carried out by auxiliary convenient equipment, such as PLC, embedded computer or router, especially produced for that purpose and through mobile network, wi-fi, or local network for being sent to joint record in server database.

In another embodiment the method is characterized by the collected data being subsequently analysed by the software that automatically or through a user intervention, produces the heat treatment reports:

- hardening reports,

- stress relief, and tempering reports,

temperature dispersion inside the furnace monitoring reports .

This application describes the use of the system for quality control of metals' heat treatment in the above paragraphs in which the method according to these paragraphs operates from the computer, laptop and as an option, from a smartphone or tablet for the:

- Hardening of steels, namely the vacuum hardening process,

- Process of stress relief, especially able for welded or tempered metals (steels and others),

- Adjustment of industrial furnaces through the knowledge of temperature variation existing inside the furnace,

validation of the quality requirements imposed by standards such as aeronautics and recommendations proposed by the North American Association for Die Casting.

General Description

This invention is included in the sector of metals' heat treatment allowing to profit by the information typically supplied by the graph recordings for a faster, more reliable and efficient later analysis, improving the evaluation of heat treatment cycle conformity imposed to the parts and able to implement further development on the thermal processes.

The main elements of this invention' s system are the following : a) Device for data acquisition: thermal treatment temperature and time from the furnace and possible additional data input by operators; b) device connection to the computer's network; c) storage of the information acquired by the device in a software database; d) data analysis through a computer software; e) automatic issuing of reports for quality control in different file formats: doc; pdf, csv, etc for reading in additional software such as e.g. word, excel, etc and also enabling them to be exported from the data processing software and/or direct printing on paper.

The existing solutions for the heat treatment graph' s analysis require special care and imply a less reliable and more demanding thermal cycle analysis. Thus, the main problems found and which are solved by this invention are the following:

1. Graphs obtained at the end phase of the treatment cycle of each production lot/batch on paper or pdf format have low resolution scales causing errors in the analysis since long cycles compress the scale, leading to difficulties in a careful analysis regarding the several steps of which cycles are composed. This problem is solved with this invention by using automatic calculation algorithms or by direct analysis on magnified scale on the furnace's screen of each stage of the cycle, or by the analysis of duly exported data to excel for further manipulation; Calculation for thermal cycle conformity verification of all stages and parameters takes a long time, but that does not occur with this invention, since the main variables of the process are automatically calculated and recorded on reports being also able to automatically validate the cycle done; In the existing systems the precision of graph analysis in pdf or paper is less than +/-5°C and +/- 15 minutes for hardening cycles, stress relief/tempering cycles and TUS - temperature uniformity survey, according the characteristics of the recording system used, thus being susceptible to relevant errors both on quality and process adjustment terms, which is not limiting the scale in this invention, since detailed digital analysis is considered in detail as well as average temperature, and deviations are automatically calculated and shown on tables. Recordings of the heat treatment cycle in graphs by itself do not sufficiently ensure the quality and better manage the heat treatment process, being important to compare the heat treatment cycle with CCT curves (Continuous cooling transformation) . This process is quite laborious and not precise in common practice, reason why it is not normally used. However, it may be implemented with the system and method of this invention;

5. There are alternative solutions to those incorporated in heat treatment furnaces. They are based on external data analysis software solutions that acquire to external dataloggers to perform post analysis with higher resolution. This software is aimed at temperature monitoring applications and can be efficiently used in the field of TUS - temperature uniformity survey, however limited regarding process analysis and issuing of complete reports on the process .

6. Current solutions provide answers to some specific needs, but do not include, simultaneously, the process, product and equipment guarantee needs, namely, they do not allow what this invention reports such as the advantage of including in the same platform the heat treatment graph, hardenability confront (CCT) ; equipment verification (TUS) and automatic calculation of the process shown in tables. This global analysis does not need to be made using distinct methods, in a laborious manner and often susceptible at low precision.

This invention is based on the use of a set of devices that allow information collection from the furnaces, storage on a database and analysis using a specific computer program for subsequent issuing and filing of 3 types of reports on a certain set of records:

Type 1 (hardening) : inclusion in the same graph report of the complete cycle graph, cooling curve drawn over the cct diagram, table containing the different heating and cooling speeds, isothermal temperatures and times of the stages at these temperatures.

Type 2 (single isothermal stage treatments) : inclusion in the same complete heat treatment cycle report and table with automatic calculation of the heating and cooling speeds, temperature and time of the isothermal stages at the same temperatures as well as heating and cooling rates.

Type 3 (TUS - furnaces Temperature Uniformity Survey) : inclusion in the same report of the details of the heat treatment graphs used for monitoring (magnification of each isothermal stage) , each report sheet contains magnified graph referring to the isothermal stage under analysis and a table corresponding to it showing the maximum and minimum values measured per thermocouple for the particular stage, the respective amplitudes and average value calculations per thermocouple and per entirety of thermocouples used, thus allowing to find furnace thermal deviations for each isothermal stage used in the furnace monitoring process.

Information collection:

It is important to have a device for collecting information about each production lot/batch through the connection of furnace thermocouples to that device. The information can be added to a set of data on the production associated with each lot/batch, that is supplied in an external manner by the operator or through a software including them.

Information storage:

There is freedom to use any platform for storing in Windows environment. The database can be encrypted to ensure safety and authenticity of the collected data. The usual devices and programs for data storage can be used for operating on a local server or on a cloud.

Data analysis in the computer program:

The computer program developed in this patent application, simultaneously enables the processing of acquired and available under, at least, 3 different types of analysis from a database enquiry:

1. Hardening cycles;

2. Stress relief and tempering cycles;

3. Furnace Temperature Uniformity Supervision (TUS)

Production and filing of different reports:

The reports produced by the program may be exported for printing and filing in different file formats, e.g.: pdf, word, excel, etc, and may be stored again in a local server or on a cloud.

Brief description of the drawings

For a more comprehensive understanding of the invention figures are attached, that represent preferred embodiments of the invention; however, they do not limit the object of the invention.

Figure 1 shows the system that includes the furnace (1), the console and automaton - HMI and PLC (2), the database (3), the computer program (4) and reports issued in different file formats (5) . Figure 2 shows in detail the device for furnace data collection, through the console and automaton - HMI and PLC (2) in which it is possible to verify the connection to the furnace through the thermocouple slots (6) and the indicators: functioning (7), record (8) and alarm (9) .

Detailed description

The system for this invention is represented in figure 1 consisting of the connection of furnace thermocouples to a data collection device with subsequent recording on a database, so that by using a specific developed software it is possible to process information collected from thermocouples, as well as additional data input by the operator through Console and Automaton ( ^λΗΜΙ - "Human Machine Interface") and PLC, converting them into useful information, namely in the production of reports for the control of the heat treatment process and quality control.

The process uses the placement of an electrical cabinet containing an HMI for data input by the operators, thus proving elements associated to the furnace data collection, such us :

1. Equipment identification;

2. Operator identification;

3. Lot/batch identification;

4. Identification of the weight put inside the furnace under treatment (optional);

These input data will be associated with furnace data (temperature) collected by auxiliary equipment convenient for the process like (PLC, embedded PC, or router especially produced for that purpose) and sent through mobile, Hi-Fi or local network for joint record on a server database .

The collected information shall be subsequently analysed by a specific software that will automatically, or with the intervention of a user, produce the heat treatment reports.

These reports are grouped into 3 categories: a) Hardening reports;

b) Stress relief/tempering reports;

c) TUS (Temperature Uniformity Survey) reports.

The system of this invention includes the elements described above, considering an electrical cabinet containing HMI with software for specific data input, and visualization, namely the input of data listed above and observation of temperatures in the various thermocouples properly identified by the program. The collection of temperature data in the device may contain different components for collection and transmission to the database according to the solution intended for the customer, namely: PLC, Router, embedded PC, etc.

Application Examples

The described method is based on the essential data collection, filing, processing stages and issuing of reports, as well as the use of a specific device and computer program as shown in figure 1 and corresponding to an industrial use in the field of metals' heat treatment, the following uses standing out: 1. Hardening process, specially dedicated to vacuum hardening of steels;

2. Stress relief and tempering process, specially dedicated to heat treatment of steels and other previously welded metals ;

3. Adjustment of industrial furnaces through the knowledge of temperature variation inside them;

4. Validation of quality requirements imposed by aeronautic standards, and recommendations proposed by the North American Die Casting Association.

These embodiments are not, naturally, in any way restricted and a person with average knowledge in the art may anticipate many possibilities of changing it, without diverting from the main essential idea, as defined in the claims .

The following claims represent additional preferred embodiments of this invention.

Claims

1. System for quality control in metals' heat treatment, implemented by computer, comprising:

- furnace ( 1 ) ,

- panel consisting of console and automaton - HMI and PLC (2),

- database ( 3 ) ,

computer software (4) that issues report in different file formats (5) .

2. System according to the previous claim, characterized in that the panel composed by console and automaton - HMI and PLC (2) are composed by thermocouple slots (6) and indicators: operation (7) record (8) and alarm (9) .

3. System according to the previous claims, characterized in that the panel composed by console and automaton - HMI and PLC (2) collects temperature and time data from the heat treatment of the furnace (1) .

4. System according to the previous claims, characterized in that the panel composed by console and automaton - HMI and PLC collects additional data input by operator .

5. System according to the previous claims, characterized in that it includes connection to the IT network.

6. System according to the previous claims, characterized in that the data are stored in computer database.

7. System according to the previous claims, characterized in that the data analysis is made through computer software .

8. System according to the previous claims, characterized in that the issuing of the reports for quality control is issued in the formats: doc, pdf, csv or other for use in other computer programs, such as, among others, word, excel, that are exported from the software or directly printed on paper.

9. System according to the pr vious claims, characterized in that the panel is compo ed of console and automaton - HMI and PLC (2) being included in an electrical cabinet .

10. Method for operating the system as described in any of the above preceding claims.

11. Method according to the previous claim, comprising the following steps:

- production data input,

- information collection,

- information storage,

- data analysis in the computer program,

- report production, issuing and filing.

12. Method according to claims 10 and 11, characterized in that the data collection stage is made through the information received from furnace thermocouples and collecting data from each lot/batch of production.

13. Method according to the previous claim, characterized in that the information is added to data externally provided by operator or software.

14. Method according to claims 10 to 13, characterized in that the step of information storage uses any storage platform in windows environment.

15. Method according to claims 10 to 14, characterized in that a step of information storage includes an encrypt database.

16. Method according to claims 10 to 15, characterized in that a step of data storage operates as local server or is placed on a cloud.

17. Method according to claims 10 to 16, characterized in that the data analysis in the software simultaneously carries out data acquisition and availability from a database enquiry, various analysis .

18. Method according to claims 10 to 17, characterized in that the distinct analysis comprises:

- Hardening cycles,

- Stress relief cycles or tempering,

- TUS (temperature uniformity survey) .

19. Method according to claims 10 to 18, characterized in that the reports produced by the software are exported for printing and filing in different formats, such as, among others, pdf, word, excel, etc and are filed again on local server or in a cloud .

20. Method according to claims 10 to 19, characterized in that the operator' s data input supplies the following elements associated to the furnace collection:

- equipment identification,

- operator identification,

- lot/batch identification.

21. Method according to claim 20, characterized in that the data the input by the operator supplies the following elements associated to the furnace collection :

- weight placed inside the furnace under treatment.

22. Method according to claims 10 to 21, characterized in that the temperature data collected from the furnace are carried out through auxiliary convenient equipment, such as, automaton - PLC, embedded pc, or router especially produced for that purpose and through the mobile, wi-Fi or local network are transmitted for joint record in server database.

23. Method according to claims 10 to 22, characterized in that the collected information is later analysed by a computer program that automatically, or with the user' s intervention, produces heat treatment reports:

- Hardening reports, - Stress relief or tempering reports

- TUS (temperature uniformity survey) reports.

24. Use of the system for quality control of metals' heat treatment according to claims 1 to 9, characterized in that the method according to claims 10 to 21 operates from a computer or a laptop, and as an option, from a "smartphone" or "tablet", for:

- Hardening process, especially dedicated to vacuum hardening of steels,

- Stress relief and tempering processes, especially suitable to the treatment of welded steel,

adjustment of industrial furnaces, through the knowledge of temperature variation inside the furnace,

- validation of the quality requirements imposed by standard referential such as aeronautic standards and North American Die Casting recommendations.