- provides know-how and technology to winners in the foundry industry © NovaCast AB ATAS - Copyright (c) NovaCast1 ATAS Verifier 4.0 Introduction to ATAS

ATAS - Copyright (c) NovaCast 1- provides know-how and technology to winners in the foundry industry© NovaCast AB

ATAS Verifier 4.0

Introduction to ATAS Verifier 4.0

Version 020531


Chemical analysis (spectrometer) shows the percentage of each element in a melt. However, it gives NO information about compounds such SiO2, FeO, silicates or dissolved oxygen that are present in the melt. These compounds determine to a large degree the nucleation status and how the dissolved carbon will precipitate as graphite during the solidification. That is why two melts with identical chemistry can behave differently when poured! Conclusion: Chemical analysis is NOT sufficient for efficient process control! Thermal analysis of samples that has been allowed to solidify according to the stable system shows what really happens thermodynamically. ATAS is not just another thermal analysis software but a metallurgical process control system. It opens a new window into the complex cast iron metallurgy. This increases the knowledge level and gives possibilities to reduce casting defects, to increase yield and to optimize the process.

ATAS - The Profession Tool for Metallurgical Process Control


ATAS Hardware

ATAS Verifier requires specialised hardware to work properly as do the other ATAS Software modules. The complete hardware consist of the following items:

1. PC computer Min. 1 GHz

2. Flat 15” TFT colour screen

3. Air-tight steel cabinet

4. High precision 16 bit A/D converter

5. UPS - Power control

6. Test stand with cable

If the foundry have a “dust” free room where they can use a normal computer then only items 4, 5 and 6 are needed.

Up to 4 test stands can be connected to the system and samples can be poured independently.


“Mini” ATAS hardware

If the foundry have a “dust” free room then a standard PC can be used.

The ATAS hardware in that case consists of

1. High precision 16 bit A/D converter

2. Test stand with cable


ATAS “The Metallurgical Fingerprint”

Thermal analysis gives the true picture of what really happens during solidification. The influence of different elements, oxides, silicates etc as well as the precipitation of carbon into graphite is reflected in the cooling curve and its first derivative. This is a “metallurgical fingerprint” that identifies the melt more accurately than traditional chemical analysis. Melts with identical “fingerprints” behave identically!. Melts with the same chemistry can behave differently!!


ATAS - 4 sampling sites

Up to 4 sampling stations can be connected to ATAS. Each station can be poured independently of the others.

ATAS Verifier works automatically. Measurement starts as soon as the cup is filled with iron.


The cooling curve

When the cooling curve is ready, important thermal parameters are calculated.

They are used by the built-in Expert System to evaluate the melt.

This screen is shown when clicking in the “local status bar”


1. Evaluation of the curve

An OK displayed on the screen means that the melt is within the specified limits and the risk for macro and micro shrinkages as well as chill etc. is minimal.

The result as well as all data are automatically stored with a time stamp for traceability according to the ISO-norm.


2. Evaluation of the curve

If a melt does not pass the test, then a ? is displayed. A click on the Risk & Explain icon gives information about why ATAS assumes that there is a risk for e.g. micro.

The alloy profile diagram shows the status for up to 10 of the most important parameters. Note that CEL and C are estimated also for grey samples.


Explaining the result

The result is explained in plain English (or the selected language) and with some possible causes.


ATAS suggests remedies

ATAS suggests a general remedy if a problem has been detected. This gives ATAS an added value. It has an educational effect and increases the metallurgical competence in the foundry.


The 1st derivative

The first derivative represents the cooling rate. It is useful in detecting various events during solidification. This screen as well as several others, is intended for the metallurgist.

For the operator it is enough to pour a sample and to look at the evaluation screen. If the result is OK then he just has to remove the Quik-Cup and ATAS is ready for a new sample. All data are saved automatically.


Statistical Process Control

All samples can be traced and displayed as in this SPC-chart. Data for various parameters can be studied, as well as control limits, average values and their standard deviation.

This screen is useful for monitoring the performance of the melting crew!


Enter your own advice!

The foundry can store their own rules and suggestions using the “Local Advisor”. In this way it is possible to customise ATAS and store local advice so that it can be used to avoid casting problems.


The Action Editor

The Action Editor is used to store new knowledge. The foundry can use up to 10 predefined rules. First the appropriate rule is selected (by clicking) then the desired action or recommendation is entered.

If the rule is triggered when a new sample is poured the desired action is displayed. Thus ATAS can gradually become more “intelligent”.


1:st derivative for a “bad” DI

1:st derivative for abad ductile iron. A powerful graphite formation in the early stages leads to lack of graphite in the end of the solidification.

It can be seen on the relative high “Max R rate” and the obtuse angle at the point of TS, “GRF 2”


Graphite picture for a “bad” DI

The corresponding graphite precipitation picture displays the same thing.


1:st derivative for a “good” DI

1:st derivative for a good ductile iron.

An elongated and relative calm graphite formation results in a casting free from shrinkage.

This can be seen on the relative low “Max R rate” and the sharp angle at the TS point.


Graphite picture for a “good” DI

The corresponding graphite precipitation picture displays the same thing


Setting Parameters

The general settings of the ATAS system are set in this screen.

Several useful features can be adjusted here.


Alloy database

The alloy database is the heart of ATAS. It is possible to enter control limits for each alloy and/or casting category.

These limits are used when evaluating new samples.


Adaptive Learning

All results are stored and sorted per alloy. The data are treated statistically by ATAS. The learning function is shown here. ATAS suggests max/min limits for the different parameters based on cases from successful pours.


Coefficients

The coefficients can be changed per alloy to increase accuracy in estimating the active carbon equivalent as well as for C and Si from white samples.

Carbon is estimated from grey samples with a special algorithm developed by NovaCast. Tests can also be made with iron treated with magnesium.


ATAS - Additional modules

• ATAS White (for testing base iron)

• ATAS Pearlite (estimates % pearlite, BHN)

• ATAS Inoculation

• ATAS Nodules (Nodularity & Nodule count)

• ATAS Research (R&D tool)


Pearlite - & BHN prognosis

After a calibration ATAS Pearlite can predict % pearlite, BHN and in some cases also Tensile.

This is especially valuable for foundries producing various

grades of ductile iron.


Nodularity & Nodule count

It is also possible to predict nodularity and nodule count.

A special calibration is needed for each type of alloy.


Coefficients Nodularity

The coefficients used to fine-tune the algorithm that estimates nodularity and nodule count must be found after some tests and entered into ATAS.


Dynamic Inoculation

In most cases the iron is over-inoculated as the chemical analysis does not give any indication of the nucleation status.

ATAS can measure the nucleation status and suggest optimal additions of inoculants.

The dynamic inoculation approach reduces problems with micro shrinkage and slag and reduces costs.


Dynamic Inoculation

The basic information about the inoculation for each alloy is entered in this screen.

The inoculation can be varied for each alloy depending on casting modulus.


Evaluating “White” samples

ATAS Verifier can also be used with tellurium-coated cups. ATAS feels that the sample has solidified “white” and adjusts its evaluation accordingly. The evaluation screen looks like this for a “white” sample.


Installing ATAS

When ATAS is installed about 20 samples of the base iron or the final iron are needed for the initial calibration. It is recommendable to take the samples randomly over 1 to 2 days in order to capture the normal variations in the iron that can not be controlled by chemistry. The learning algorithm in ATAS suggests suitable limits for each alloy. Specialists from NovaCast are usually present to assist the foundry during this phase.


Taking into operation

ATAS can be used in production after the initial calibration and as a quality assurance tool both for base and final iron. At this stage ATAS can also act as an early warning indicator for casting defects. ATAS gives some general suggestions for remedies to avoid defects. This advice can gradually be tailored by the foundry using the Local Advisor system.


Why ATAS Verifier?

• Method for quality assurance• Method for process optimization• Increases metallurgical competence• Reduces casting defects• Gives possibility to increase yield• Reduces alloy consumption• Less variations in physical properties• Savings per ton up to $ 50 or more!

ATAS Verifier

for effective

metallurgical

process

control


Your Technology Partner

NovaCast´s ambition is to be your partner in foundry technology. We can not only teach foundry personnel to use ATAS but also assist them in solving metallurgical problems, to reduce casting defects and improve yield.

Contact us!NovaCast ABSoft CenterSE-372 25 Ronneby, SwedenTel: +46 457 386 300 Fax:+46 457 156 22E-mail: [email protected]

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- provides know-how and technology to winners in the foundry industry © NovaCast AB ATAS - Copyright (c) NovaCast1 ATAS Verifier 4.0 Introduction to ATAS