Materials Algorithms Project
Program Library

Program MAP_STEEL_WELDSOFT

1. Provenance of code.
2. Purpose of code.
3. Specification.
4. Description of subroutine's operation.
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

Billy Chan & Malcolm Bibby,
Department of Mechanical and Aerospace Engineering,
Carleton University,
Ottawa,
Ont. K1S 5B6, Canada.

Program added: April 1999

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Purpose

The software is designed for professionals involved with welded fabrication - welding engineers, consultants or specialists associated with large fabrication facilities, mechanical design engineers or material engineers. It is often necessary for engineers to specify welding parameters and conditions for a given job at the design stage or in consultation with fabrication specialists. Traditionally, specifications have been based on either long experience or on trial run activities. This software provides some guidance where the criteria involve heat-affected zone (HAZ) hardness, reheat or preheat weld treatment, or weld size and shape.

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Specification

Complete program. Also included are a number of data files which can be read by the program.

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Description

The software contains four relatively independent modules:

The size and shape of a weld are important operating variables in fabrication practice. In general, the larger the weld area, the fewer the number of passes necessary to fill a given joint. However, this also depends on its shape. Optimising the process to minimise the number of passes is an important productivity exercise. Moreover the bead shape and size influence the cooling rate and dilution from the base plate, which affect the mechanical properties. The weld shape module consists of 4 sub-modules:

(i) Gas metal arc welding (GMAW)

Bead-on-plate welds fusion zone size and shape - calculated from algorithms established by Chandel [1], based on a regression analysis of a very large experimental data base.

(ii) Submerged arc welding (SAW)

Bead-on-plate welds fusion zone size and shape - calculated from algorithms established by Chandel et al. [2], McGlone et al. [3] and two models by Yang et al. [4].

(iii) Submerged arc welding with Y-groove plate preparation and single electrode (SAW Y 1e)

Bead-on-plate welds fusion zone size and shape - calculated from algorithms by McGlone et al. [3] and three models by Yang.

(iv) Submerged arc welding with Y-groove plate preparation and twin electrodes (SAW Y 2e)

Bead-on-plate welds fusion zone size and shape - calculated from algorithms by Yang.

(b) As-Welded HAZ Hardness Module

This module calculates the heat-affected zone (HAZ) hardness of welds from the welding parameters and the base metal composition. The module is based on relatively independent algorithms generated for this purpose from the investigations of Arata [5], Yurioka et al. [6], Suzuki [7], Terasaki [8], Dueren [9], Beckert and Hoz [10] and Cottrell [11]. The weld cooling time from 800 to 500 deg. C, required in all models, is obtained from the Adams heat transfer relationships [12].

(c) Reheat Hardness Module

Post weld heat treatment is applied to a weldment to reduce residual stress levels which, among other things, decreases the sensitivity of a joint to corrosion. It may also lower the HAZ hardness and thereby increase the toughness of this region. This module is based on a regression model proposed by Okumura et al. [13]. It calculates the as-welded HAZ hardness and then determines the change in hardness due to the post weld heat treatment. Adams [12] heat transfer relationships are used to calculate the 800 to 500 deg. C weld cooling time.

(d) Preheat Treatment Module

If the weld cools rapidly, hydrogen can get trapped in the HAZ in a supersaturated state; this greatly enhances the probability of underbead crack formation. Preheat is used to slow down the weld cooling process. A sufficiently high preheat temperature will slow down the cooling rate and keep the weld above 100 deg. C to allow the hydrogen level to drop below a critical level [14]. The time required for this to occur, and the amount of preheat required, depends on the chemical composition of the workpiece, the stress level, the hydrogen level generated by the heat source and the dimensions of the workpiece. The heat transfer model of Satoh and Matsui [15] is used to calculate the residence time above 100 deg. C. The preheat module determines the critical 1500 to 100 deg. C cooling time, and from that a suitable preheat temperature to avoid underbead cold cracking.

Files for Downloading

man*.doc and man*.ps

A user manual, written using WordPerfect 5.1 for MSDOS (also readable by Microsoft Word version 6.0 or higher). Postscript files of each chapter are also provided.

manual.txt and manual.rtf

A version of the manual in RTF and text format, but without any figures.

weldsoft.exe

The executable program.

weld2.ovr

Essential for the running of the program. It must be placed in the same directory as the executable file.

*.ste, *.haz, *.gma, *.ste, *.pre, *.reh, *.yg1

Data files which can be read into the program if desired.

p*.jpg

Help pages - accessed from the program.

Installing and Running Weldsoft
Place weldsoft.exe, weld2.ovr, the data files and the p*.jpg files into the same directory on either the hard disc or floppy disc. To start the program either type weldsoft at an MSDOS prompt or (in windows) double click on the file weldsoft.exe.

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References

1. R.S. Chandel, 1989, An Investigation into the Electrode and Plate Melting Efficiencies of SAW and GMAW Process, Report MTL 89-10J, Metals Technology Laboratories, CANMET/EMR, Government of Canada, Ottawa, Ontario K1A OG1, Canada.
2. R.S. Chandel, 1989, Australian Welding Journal, First Quarter 1989, pp 23-25.
3. J.C. McGlone and D.B. Chadwick, Dec. 1978, The Welding Institute Report No. 80/1978/PR, The Submerged Arc Butt Welding of Mild Steel Part 2: the Prediction of Weld Bead Geometry from the Procedure Parameters.
4. L.J. Yang, M.J. Bibby and R.S. Chandel, 1992, Modelling the Submerged-Arc Welding Process Using Linearing Regression Equations, 3rd Conference on Trends in Welding Research, Gatlinburg, Tennessee, USA, June 1-5, 1992.
5. Y. Arata, K. Nishiguchi, T. Ohji and N. Kohsai, 1979, Trans. J. Jap. Welding Research Institute, 8(1), 43.
6. N. Yurioka, M. Okumura and T. Kasuya, 1987, Metal Construction, 19(4), pp 217R-223R.
7. H. Suzuki, 1984, Trans. J. Jap. Welding Society, 15(1), 25-33.
8. T. Terasaki, 1981, Journel of ISIJ, 16, 145-152.
9. C. Dueren, 1985, IIW DOC IX-1358-85 3R International, 24 Jahrgang, Heft.
10. M. Beckert and R. Hoz, 1973, Schw. Tech., 23(8), 344.
11. C.L.M. Cottrell, 1984, Metal Construction, 16, 740-744.
12. C.M. Adams, 1958, Welding Journal AWS, 37, 210.
13. M. Okumura, N. Yurioka, T. Kasuya and H.J.V. Cotton, IIW Int. Conf. on Residual Stress and Stress Relieving, Sofia, Bulgaria, July 6-7, 1987, pp 61-68. Prediction of HAZ Hardness after PWHT.
14. N. Yurioka, H. Suzuki, S. Ohshita and S. Saito, 1983, Welding Journal, 62, 147.
15. K. Satoh and S. Matsui, 1971, Journel of JWES, 40, 1117.
16. B.K.H. Chan, 1990, Master Thesis, Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada. Software for Welding Engineers.
17. Further references are given in the manual and on the help pages in the program.

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Parameters

Input parameters:

Welding current (Amps)

Welding voltage (Volts)

Welding speed (mm/s)

Electrode diameter (mm)

Electrode extension (mm)

Polarity (+/-)

Gas type - GMAW only

Plate thickness (mm) - SAW Y 1e and 2e only

Groove angle (deg.) - SAW Y 1e and 2e only

Root height (mm) - SAW Y 1e and 2e only

Output parameters:

Total fusion area (mm²)

Deposited weld area (mm²)

Bead height (mm)

Bead width (mm)

Penetration (mm)

Melt rate (kg/hr) - GMAW and SAW only

Reinforced boundary length (mm) - GMAW only

Fusion boundary length (mm) - GMAW only

Input parameters:

Welding current (Amps)

Welding voltage (Volts)

Initial (ambient) temperature (deg. C)

Plate thickness (mm)

Welding speed (mm/s)

Process efficiency (%)

Composition of steel (wt%) (C, Mn, Si, Ni, Cr, Mo, V, B, Cu, Nb, N, S)

Output parameters:

HAZ hardness values (8 different models) (VHN)

Fraction of martensite (2 different models)

Weld cooling time from 800 to 500 deg. C, t_8/5 (s)

Input parameters:

Welding current (Amps)

Welding voltage (Volts)

Initial (ambient) temperature (deg. C)

Plate thickness (mm)

Welding speed (mm/s)

Process efficiency (%)

Reheat temperature (deg. C)

Reheat time (hours)

Composition of steel (wt%) (C, Mn, Si, Ni, Cr, Mo, V, B, Cu, Nb)

Optional - experimental value for the weld cooling time from 800 to 500 deg. C, t_8/5 (s)

Output parameters:

Weld cooling time from 800 to 500 deg. C, t_8/5 (s)

As-welded HAZ hardness value (VHN)

Post-weld reheat HAZ hardness value (VHN)

Input parameters:

Welding current (Amps)

Welding voltage (Volts)

Ambient temperature (deg. C)

Plate thickness (mm)

Welding speed (mm/s)

Process efficiency (%)

Hydrogen level (ml/100g)

Restraint coefficient rf (N/mm³)

Yield strength (MPa)

Stress concentration factor Kt

Composition of steel (wt%) (C, Mn, Si, Ni, Cr, Mo, V, B, Cu, Nb)

Type of preheat - uniform/local/torch/electrical strip

- workpiece length (mm)

- workpiece width (mm)

- heater intensity (J/mm²)

- heater width (mm)

Output parameters:

Cooling time from 1500 to 100 deg. C, t_15/1 (s)

Preheat temperature (deg. C)

Preheat time (s) - if applicable

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Error Indicators

Violations of the regression limits are indicated.

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Accuracy

No information supplied.

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Further Comments

All the modules are based on regression models and, therefore, are subject to certain working limits of the input parameters (given in the manual). In general, the mathematical relationships are valid for low alloy steels with carbon content less than 0.3wt%. In order to ensure that these limits are not violated, the limits active option in the program can be selected. It is often interesting, however, to explore beyond the limits; it is left to the user to use the software wisely!

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Example

1. Program text

Complete program.

2. Program data

3. Program results

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Auxiliary Routines

None.

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Keywords

weldsoft, weld, welding, hardness, heat treatment, weld shape, steel

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Download

Download program files
Download program manual

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