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Program MAP_STEEL_MS_EMPIRICAL_2014

  1. Provenance of code.
  2. Purpose of code.
  3. Specification.
  4. Description of program.
  5. References.
  6. Parameter descriptions.
  7. Error indicators.
  8. Accuracy estimate.
  9. Any additional information.
  10. Example of code
  11. Auxiliary subroutines required.
  12. Keywords.
  13. Download source code.
  14. Links.

Provenance of Source Code

Mathew Peet
Phase Transformations and Complex Properties Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.

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Purpose

Simple program in C which implements empirical equations for martensite start temperature. Then combines the models to estimate the MS (from average of the models) and uses standard deviation to give an estimate of model certainty.

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Specification

Language: ANSI C
Product form: Source code.

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Description of Program

Implementation of empirical equations.

  1. Ms(oC)=539.0-423.0*Cwt-30.39*Mnwt-12.14*Crwt-17.69*Niwt-7.46*Mowt[Ref 1]
  2. Ms(oC)=531.0-391.2*Cwt-43.3*Mnwt-21.8*Niwt-16.2*Crwt[Ref 2]
  3. Ms(oC)=539.0-423.0*Cwt-30.4*Mnwt-12.1*Crwt-17.7*Niwt-7.5*Mowt+(10.0*Cowt-7.5*Siwt)[Ref 3]
  4. Ms(oC)=561.0-476.0*Cwt-33.0*Mnwt-17.0*Crwt-17.0*Niwt-21.0*Mowt+(10.0*Cowt-7.5*Siwt)[Ref 3]
  5. Ms(oC)=561.0-476.0*Cwt-33.0*Mnwt-17.0*Crwt-17.0*Niwt-21.0*Mowt[Ref 4]
  6. Ms(oC)=560.5-(407.3*Cwt+7.3*Siwt+37.8*Mnwt+20.5*Cuwt+19.5*Niwt+19.8*Crwt+4.5*Mowt)[Ref 5]
  7. Ms(oC)=521.0-353.0*Cwt-22.0*Siwt-24.3*Mnwt-7.7*Cuwt-17.3*Niwt-17.7*Crwt-25.8*Mowt[Ref 6]
  8. Ms(oC)=550.0-361.0*Cwt-39.0*Mnwt-35.0*Vwt-20.0*Crwt-17.0*Niwt -10.0*Cuwt-5.0*Mowt+15.0*Cowt-30.0*Alwt [Ref 7]
  9. Ms(oC)=550.0-350.0*Cwt-40.0*Mnwt-35.0*Vwt-20.0*Crwt-17.0*Niwt-10.0*Cuwt-10.0*Mowt-10.0*Wwt-0.0*Siwt+15.0*Cowt [Ref 8]

No error checking exists, no account of the range of applicability of the formulae is made.

The MS temperature is calculated according to each of the above equations, the average and standard deviations of these results is then used to calculate the estimated MS temperature, and an assessment of the model uncertainty. Combining the best 11 peforming models was shown to provide the best performing model.[Ref 10]

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References

  1. Andrews K. W., Empirical formulae for the calculation of some transformation temperatures, J.I.S.I., 203 (1965) 721-727.
  2. G. T. Eldis, Proceedings of the Symposium on the Hardenability Concepts with Application to Steel, 1977.
  3. C. Y. Kung and J. J. Rayment, Title, Metall. Trans. A. 13 (1982) 328.
  4. W. Steven and A. G. Haynes, The temperature formation of martensite and bainite in low-alloy steels, some effects of chemical composition, J. Iron Steel Inst., 183 (1956) 349-359.
  5. T. Kunitake, Prediction of Ac1, Ac3, and MS temperatures of steel by empirical formulas, J. Jpn. Soc. Heat Treat., 41 (2001) 164-169.
  6. T. Kunitake and H. Ohtani, Calculating the Continuous Cooling Transformation Characteristics of Steel from Its Chemical Composition, Sumitomo Search, 2 (1969) 18-21.
  7. I. Tamura, Steel Material Study on the Strength, Published by Nikkan Kogyo Shinbun Ltd, Tokyo (1970).
  8. K. Monma, Tekko-zairyo-gaku, Chapter 'Martensite', Published by Syuppan Corporation, (1972) in Japanese language.
  9. Mathew Peet, MAP_STEEL_MS_EMPIRICAL (version 3.1), 2007
  10. Mathew Peet, Prediction of Martensite Start Temperature, Materials Science and Technology, 31 (11), 1370--1375.

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Parameters

Input parameters

Composition in weight percent of carbon, manganese, silicon, chromium, nickel, molybdenum, vanadium, cobalt, aluminium, tungsten, copper, niobium, nitrogen, zirconium, tantalum, hafnium.

Output parameters

Martensite start temperatures and estimate of error in Fahrenheit and Celcius.

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Error Indicators

No assessment of errors is made.

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Accuracy

No information supplied.

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Further Comments

None.

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Example

1. Program text

       N/A - complete program

2. Program data

Enter Composition in weight precent to predict Martensite start temperature
Carbon?
0.2
Manganese?
1.1
Silicon?
0.34
Chromium?
0.011
Nickel?
0.02
Molybdenum?
0.008
Vanadium?
0.009
Cobalt?
0
Aluminium?
0.036
Tungsten?
0
Copper?
0.018
Niobium?
0.003
Nitrogen?
0
Zirconium?
0
Tantalum?
0
Hafnium?
0

3. Program Results

Martensite Start Temperature
----
Average of 'Best 11'		813.8 F  420.1 C
Standard Deviation		 59.4 F   33.0 C
----

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Auxiliary Routines

None

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Keywords

Martensite, start temperature, Ms

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Download

Download source code.

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MAP originated from a joint project of the National Physical Laboratory and the University of Cambridge.