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Hello,

I am looking for some guidance. I've been wondering if there are any means to calculate a speculated hardness profile of a carburized cylinder without dedicated software. Assume it's a semi-infinite cylinder, and that the carbon potential, soaking temperature, chemistry are known. Shouldn't one be able to make predict the profile relatively easily?

Thanks,

Ife

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Ife Siffre
Engineering Specialist
Ford Motor Company
Detroit MI
(816) 778-5630
------------------------------

High Ife,

there are indeed several software suppliers who are offering software for the prediction of carburizing AND hardness profiles.

While I don't want to advertise any of them specifically, I am frequently working and consulting interested customers - now for almost 3 decades - successfully by using trhe software HT-Tools V3.0e from Process-Electronic, member of the United Process Controls Inc.

With this software, you can get good predictions of the hardness profiles of carburized parts. The predictions are - as I found out over the years - pretty close to the actual results, provided that you are careful in selecting the parameters, that you have to define by yourself (such as dimesnional reference data, mean values of alloy constituents, expected quench severity of the quenchant that you use and depending upon the intensity of your quench agitation).

As matter of fact, you can not only predict the hardness and carbon content curves in general but this software is most valuable for optimizing the treatment parameters and subsequently make the whole process more efficient and less costly.

Hope to have helped you  ... kind regards

 

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Helmut Egger
EGGER Consulting GmbH
ARNSBERG
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Hi Ife,

it is me again.   I was overlooking in my previous reply, that you want to predict the hardness profile without dedicated software.

I'd say NO, that's NOT possible.  The hardness profile is depending on so many factors, most important on each alloy constituents, so that an easy estimate just isn't possible.

The same is applicable also for the carburizing profile as well.

 

------------------------------
Helmut Egger
EGGER Consulting GmbH
ARNSBERG
egger.consulting@t-online.deGermany
------------------------------

Thanks for the insight. I really appreciate your response.

------------------------------
Ife Siffre
Engineering Specialist
Ford Motor Company
Detroit MI
(816) 778-5630
------------------------------

Original Message:
Sent: 03-15-2023 08:26
From: Helmut Egger
Subject: Predicting Hardness Profile of Carburized Parts

Hi Ife,

it is me again.   I was overlooking in my previous reply, that you want to predict the hardness profile without dedicated software.

I'd say NO, that's NOT possible.  The hardness profile is depending on so many factors, most important on each alloy constituents, so that an easy estimate just isn't possible.

The same is applicable also for the carburizing profile as well.

 

------------------------------
Helmut Egger
EGGER Consulting GmbH
ARNSBERG
egger.consulting@t-online.deGermany
------------------------------

It is possible, but you need to be aware of the limitations. Careful application of your results is required until any model is tested and qualified. There are numerous formulas that have been developed over the years to predict carbon profile. These formulas can be entered into a spreadsheet and will give a good approximation of carbon profile. You can then use hardenability data from your specific alloy to predict hardness. This will work best if you have the opportunity to tweak your model using real life data as these formulas are always a bit idealized. I have a spreadsheet that I have adjusted for my components that works fairly well.

A good source carburizing in general is this doctoral thesis by Olga Rowan of Caterpillar: https://digital.wpi.edu/concern/etds/tt44pm955?locale=en

This paper includes a table with various carbon diffusivity formulas which you can try.

Good luck!

------------------------------
Allen Fuller
Metallurgy Manager
Amsted Rail Company, Inc.
Chester VA
(804) 454-6186
------------------------------

I've heard of her work from a professor of mine. I will review the content. Thanks for the link. 

------------------------------
Ife Siffre
Engineering Specialist
Ford Motor Company
Detroit MI
(816) 778-5630
------------------------------

Original Message:
Sent: 03-15-2023 08:48
From: Allen Fuller
Subject: Predicting Hardness Profile of Carburized Parts

It is possible, but you need to be aware of the limitations. Careful application of your results is required until any model is tested and qualified. There are numerous formulas that have been developed over the years to predict carbon profile. These formulas can be entered into a spreadsheet and will give a good approximation of carbon profile. You can then use hardenability data from your specific alloy to predict hardness. This will work best if you have the opportunity to tweak your model using real life data as these formulas are always a bit idealized. I have a spreadsheet that I have adjusted for my components that works fairly well.

A good source carburizing in general is this doctoral thesis by Olga Rowan of Caterpillar: https://digital.wpi.edu/concern/etds/tt44pm955?locale=en

This paper includes a table with various carbon diffusivity formulas which you can try.

Good luck!

------------------------------
Allen Fuller
Metallurgy Manager
Amsted Rail Company, Inc.
Chester VA
(804) 454-6186
------------------------------

Hi Ife,
Nice to hear from you.
This is a complex process. There are some ways to predict this hardness. For example, you can use ThermoCalc and the diffusion module Dictra, to predict the chemistry profile during the carburizing step. 
Using the predict chemistry profile, you can use the hardenability ASTM A255 standard to predict the hardness for each position assuming a low quench severity factor. 
Let me know if you need any guidance.
Best regards.

------------------------------
Mario Buchely
Assistant Professor
MISSOURI S&T
Rolla MO
5733416972
------------------------------

Mario,

Hope all is well! I suspect that I will use something akin to the Dr. Van Aken's calculator. It would be a modified version of course. We have access to Dante and various other resources here. My first step is just developing a basic ideal model that I can manipulate easily. That data will then be fitted to real data that we have.

------------------------------
Ife Siffre
Engineering Specialist
Ford Motor Company
Detroit MI
(816) 778-5630
------------------------------

Original Message:
Sent: 05-17-2023 09:16
From: Mario Buchely
Subject: Predicting Hardness Profile of Carburized Parts

Hi Ife,
Nice to hear from you.
This is a complex process. There are some ways to predict this hardness. For example, you can use ThermoCalc and the diffusion module Dictra, to predict the chemistry profile during the carburizing step. 
Using the predict chemistry profile, you can use the hardenability ASTM A255 standard to predict the hardness for each position assuming a low quench severity factor. 
Let me know if you need any guidance.
Best regards.

------------------------------
Mario Buchely
Assistant Professor
MISSOURI S&T
Rolla MO
5733416972
------------------------------

Dear Ife,
Dr. Van Aken developed his workbook for hardenability purposes, but it can be used to predict hardness of each steel. You need to know the chemical compositon though, and that is why I susggested ThermoCalc. 
Dante use a basic diffusion model for C and N, and it does a descent job. However, it is limited for the data base of material that Dante Software has developed. If you want to check a different alloy, the results are not accurate. So, the Dictra Module in ThermoCalc could be implemented to solve the mass trasfer problem and obtain a final quemestry after carburizing. It is imporatant to say that diffusivity models in ThermoCalc are very complex, and involved the interaction of different elements (not just C and N), thus the results are much more accurate.
Let me know.
Regards.

------------------------------
Mario Buchely
Assistant Professor
MISSOURI S&T
Rolla MO
5733416972
------------------------------

Original Message:
Sent: 05-17-2023 09:28
From: Ife Siffre
Subject: Predicting Hardness Profile of Carburized Parts

Mario,

Hope all is well! I suspect that I will use something akin to the Dr. Van Aken's calculator. It would be a modified version of course. We have access to Dante and various other resources here. My first step is just developing a basic ideal model that I can manipulate easily. That data will then be fitted to real data that we have.

------------------------------
Ife Siffre
Engineering Specialist
Ford Motor Company
Detroit MI
(816) 778-5630
------------------------------


Original Message:
Sent: 05-17-2023 09:16
From: Mario Buchely
Subject: Predicting Hardness Profile of Carburized Parts

Hi Ife,
Nice to hear from you.
This is a complex process. There are some ways to predict this hardness. For example, you can use ThermoCalc and the diffusion module Dictra, to predict the chemistry profile during the carburizing step. 
Using the predict chemistry profile, you can use the hardenability ASTM A255 standard to predict the hardness for each position assuming a low quench severity factor. 
Let me know if you need any guidance.
Best regards.

------------------------------
Mario Buchely
Assistant Professor
MISSOURI S&T
Rolla MO
5733416972