Pieter van der Wolk
Heat Treatment Science and Technology Group
Laboratory of Materials Science
Delft University of Technology
Rotterdamseweg 137
2628 AL Delft
Contact: P.J.vanderWolk@STM.TUDelft.nl
Provides a database giving Ms data for steels of various composition, and a trained neural network model (provided as a spreadsheet) for calculating Ms temperatures for steels of arbitrary composition.
The distribution contains three types of file, as described :-
MS.TXT is an tab-delimited ASCII text file containing a database of steel compositions and their martensite start temperatures. Each row represents one steel composition. Columns are :-
Columns 1 and 2 give the Ac3 temperature and the austenising temperature respectively (in Kelvin).
Columns 3-19 specify alloying element in mass%. The elements are :-
Alloying elements which were not specified in the original paper have been set to zero.
Column 20 gives Martensite start temperature in Kelvin.
Column 21 gives a reference number; the meaning of these reference numbers is listed at the
bottom of the file, and in the reference list below.
MsANN.WK1 and MsANN.xls contain a neural network model converted into
LOTUS1-2-3
and EXCEL3
formats respectively.
After editing the cells with the alloying elements (B5..B16) the Ms-temperature (F8..F10) is updated automatically according to the neural network model. The model is incorporated in the spreadsheet below row 18.
The neural network model has been trained with 311 steel compositions from the above database; 233 data have been used to calibrate the model, and 78 data have been used to validate the model.
It is a hierarchical feed-forward backpropagating neural network with a 12:5:1 architecture. For a detailed description, see [5].
Testing the modelThe initial steel composition gives :-
Constituent | Mass% | Ms Temp (Kelvin) |
---|---|---|
C | 0.2000 | 718.0 |
Si | 0.2500 | |
Mn | 0.7000 | |
P | 0.0010 | |
S | 0.0005 | |
Ni | 0.1000 | |
Cr | 0.3500 | |
Mo | 0.0100 | |
V | 0.0000 | |
Cu | 0.0000 | |
Al | 0.0200 | |
N | 0.0050 |
If the following compositions give the indicated Ms temperatures, the model is working properly.
Constituent | Mass% [1] |
Ms Temp (Kelvin) [1] |
Mass% [2] |
Ms Temp (Kelvin) [2] |
---|---|---|---|---|
C | 0.6000 | 523.3 | 0.1100 | 722.6 |
Si | 0.4800 | 1.0000 | ||
Mn | 1.6100 | 0.5000 | ||
P | 0.0140 | 0.0000 | ||
S | 0.0280 | 0.0000 | ||
Ni | 0.0500 | 0.9000 | ||
Cr | 1.0000 | 0.0300 | ||
Mo | 0.0200 | 0.1000 | ||
V | 0.1600 | 0.0000 | ||
Cu | 0.1000 | 0.0000 | ||
Al | 0.0220 | 0.0000 | ||
N | 0.0070 | 0.0000 |
None.
materials, data, neural, network, martensite, start temperature, steel, composition, concentration, start, temperature
MAP originated from a joint project of the National Physical Laboratory and the University of Cambridge.
MAP Website administration / map@msm.cam.ac.uk