Welding economics

1.Arc welding economics

Welding processes in arc welding: SMAW,GTAW,GMAW,SAW,EGW,

EGW,Plasma  are all employed for many industrial components.Welding costs estimation plays an important role in fabrication to calculate profit.Welding costs estimation for any specific process used in fabrication should understand components

of Total cost: cost of consumables(filler,fluxes,gases),labour costs,power cost,overheads.

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Welding expertise

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SMAW

Weight of weld metal:

Volume of weldmetal*Density

Volume of weld metal:

Area as per edge preparation *length of weld

No of electrodes required:

Volume of weld metal per electrode:Electrode area*length of electrode consumed.

Number of electrodes required :

Volume of weld metal /electrode volume

Weld metal cost :

Cost per electrode*number of electrodes consumed.

Power cost:

Arc time per weld and units consumed (kwhr) and total unit cost

Labour cost.

Total hrs per weld*wages per hour

Other costs

Overheads

Miscellaneous costs

Sum of all costs gives welding cost estimation for length of weld

GTAW

Shielding gas cost :

flow rate (L/min)*arc time *cost/litre

Filler rod consumed :

area of cross section*length of rod consumed *density (kg)

cost/kg* amount of filler consumed during arc time : cost of filler

Total cost = cost of filler+ cost of shielding gas + power cost + labour cost + over head

Submerged arc welding

Total cost should include cost of filler,cost of flux,power cost,labour and overhead.

Affordable Online up-skill welding courses

Course titles
Schedule
Faculty
Purpose

1.Affordable On-line up-skill welding courses .

These affordable courses on  welding technology are essential as it is a complex technology involving all disciplines of engineering : Mechanical,metallurgical,electrical,electronics,civil,computer science and production .Practicing   engineers find short term online up skill specialised welding courses useful for refreshing and to implement in industries latest trends.

Latest trends

Welding Education and training

http://www.twitraining.com

http://www.aws.org.com

http://www.iiw.com

https://images.app.goo.gl/XuxM6HTHywLPugBA7

2. Course titles:Eligibility,Contact mail

The following programmes will be conducted online for small batches for better interaction and to gain in depth knowledge.

1. Welding process technology I     2 days ( 6 hrs per day) Saturdays and Sundays

All arc welding processes required for industries will be covered.

2.Welding process Technology II     2 days ( 6 hrs per day) Saturdays and Sundays

3.Design ,distortion,and control     2 days

4.Weldability of ferrous and non ferrous alloys  2 days

All other advanced welding processes are covered with applications.

Experienced candidates with diploma, engineering qualification  as well as fresh engineering graduates(3 and 4 sem) from India can apply .

Interested candidates can contact for getting details of fees and schedule .Group booking can be done as per guidelines.Link will be provided in advance for attending online courses as per schedule.

Mail address for contact :

kgk.murti@gmail.com

3. Schedule

The number of candidates per course is limited to maximum 15.

 

4.Benefits

These courses will be useful also  as preparatory courses for Welding engineers and welding inspector certification programs.

5.Faculty:

Dr.KGK Murti

Qualification : B Tech (Mech);M Tech ( welding);IIT Chennai.P h.D

(welding) NIT Trichy.

Experience: 30 years in Welding research institute and BHEL Trichy.

Trained in Germany,France.Visited Russia and Japan

Presented more than 80 papers and guided 6 Ph.D welding students

Worked as professor for 15 years in GRIET,IARE Hyderabad.Won several awards during the last 45 years of experience in industry and academics.

6.Purpose of affordable on-line Up-skill welding courses.

These courses are planned as no loss no profit basis to promote

welding technology and benefit welding professionals.

Several week end courses are planned on all major topics.Those interested can communicate giving topics of current interest to include.Certificate will be given on successful completion of course which will be useful for resume and placements.

Welding placements and skills needed
Welding professionals are always needed in industries for both shop floor and site welding jobs.

Welders skill requirements

1. Welding process knowledge(SMAW,GMAW,GTAW etc)

2.Basic metallurgy( Metals,non-metals,physical and mechanical properties,Metallography,HT etc)

3.Design of welds( Edge preparation, welding symbols,types of welds,plate and pipe welds,welding positions etc)

4.Destructive tests for evaluation of weld quality

5.Non destructive tests and applications.

6.Basic mathematical skills(calculating dimensions,understanding sketches,reading drawings,2D,3D,spatial reasoning)

7.Attention to detail( material preparation,cleaning,perfection in workmanship,etc)

8.Hand- eye coordination

9.Stamina to work in various situations

10.Ability to learn new things

11.Communication skills and team working .

12.Welding health and safety.

13.Codes and standards knowledge

14.Welding defects and acceptance criteria.

Those with sufficient training,adequate qualification and certification  can prepare a good resume and apply for posts regularly announced through important websites.

http://www.naukri.com

http://www.careers in welding.com

http://www.placementindia.com

Certified welding engineers

International institute of welding offers certified welding engineers programme which is recognised in many countries.

IWE : International welding engineer (IIW)
IWE – Knowledge, Competence and Management
A candidate completing the IWE training under this program is expected to acquire advanced knowledge and critical understanding of welding technology application.
He / she shall have advanced competence and skills at a level that is required in the field of welding technology which demonstrate:

1.Technology mastery and required innovation

2.Being able to solve high-level complex and unpredictable problems
3. The ability to manage high complex technical and professional activities or projects related to welding applications
4.Taking responsibility for decision making in unpredictable work or study context
5. Taking responsibility for managing professional development of individuals and groups

Thoretical and practical sessions to give in-depth knowledge are offered .Four modules have to be completed and examination will be conducted after each module.

Module 1: Welding processes and equipment.

Module 2: Materials and behaviour during welding

Module 3:Construction and design

Module 4:Fabrication and application engineering

After successful completion of all the modules ,certificate will be issued (IWE)

AWS certified welding engineer(CWEng)

A person with the demonstrated education, experience, and knowledge as defined by this information and who successfully passes the required examinations is considered qualified as an AWS Certified Welding Engineer (CWEng).

The CWEng is capable of directing those operations associated with weldments and other types of joints that are completed in accordance with the appropriate contract documents, codes, and other standards to produce a satisfactory product. The welding engineer¹s activities begins before production or construction welding and continues through the production process then ending when the production process is complete.

Each employer is responsible for defining the specific duties of the CWEng in place of employment.

Great opportunities exist for AWS certified welding engineers all over the world.

Certified welding inspector(CWI)

Certified Welding Inspectors (CWI) must demonstrate a keen attention to detail along with other requisite knowledge, skills, and abilities, and are often considered the safety nets that catch potentially catastrophic mistakes.

It’s the CWI’s responsibility not only to determine if a weldment meets the acceptance criteria of a specific code, standard, or other specification, but also to handle qualification records, oversee non-destructive testing and ensure proper materials are available during testing.

Therefore, it is important that the CWI is familiar with welding processes, welding procedures, welder qualifications, materials, and weld testing limitations, as well as how to read blueprint drawings, prepare and keep records, prepare and make reports, and make responsible judgments.

AWS gives CWI which is very valuable and recognised in many countries.

CSWIP welding inspector

A qualification in CSWIP Welding Inspection from TWI can open doors to rewarding and varied careers anywhere in the world for welding inspectors. The welding inspection certification courses offer a clear career path starting with the visual weld inspection training.

Many contractors now cite CSWIP certification as a requirement for employment in this area, to prove you can perform work to a safe and professional standard, while also helping to reduce the cost and time spent on rework or repairs and ensuring projects are delivered on time.

Completing a welding inspection course and gaining a qualification provides a thorough understanding of the role and the confidence to perform it to a high standard. In addition, welding technology knowledge gained from CSWIP welding inspection courses will help support your development of responsible welding coordinator competence

Please refer for detailed information websites.

http://www.aws.org

http://www.twitraining.com

 

 

Welding codes and standards

Welding professionals should possess knowledge on various codes

and standards for successful fabrication of products.Some important codes and standards have world wide acceptance.Wealth of information by experts  is incorporated in these reference materials.

 

http://www.asme.org

http://www.api.org

 

http://www.aws.org

http://www.iso.org

Approach for preparation of codes and standards

AWS Standard Welding Procedure Specification (SWPS)

Procedures that have been qualified by the Welding Research Council and accepted and published by AWS for use as a qualified welding procedure


Welding Education and training

Welding Procedure Qualification (PQR)

A test that is performed to demonstrate that the contractor can make satisfactory welds as specified in the Welding Procedure Specification

Mechanical testing is required and NDE may be required, depending on the Code being qualified to
Impact testing may be required by the referencing Code (i.e., ASME Sect VIII)

Guidelines for Quality records

Quality records shall be retained for a minimum period of five years in the absence of any other specified requirements.
Quality records shall include, when applicable:
– record of requirement/technical review;
– material certificates;
– welding consumable certificates;
– welding procedure specifications;
– equipment maintenance records;
– welding procedure approval records (WPQR);
– welder or welding operator qualification certificates;
– production plan;
– non-destructive testing personnel certificates;
– heat treatment procedure specification and records;
– non-destructive testing and destructive testing procedures and reports;
– dimensional reports;

Welding Tips for practice                

1 Mild steel electrodes:E 6010,E6011,E6012,E6013
2.Use DCEP for E6010 when used for mild steel and
low alloy steels required for ship building,construction,bridges,tanks,piping.
3.AC/DC can be used for E6012 for flat and horizontal positions.
4.Use E6012 when fitup is a problem.
5.E6013 can be used with AC/DC and has very good
slag detachability.Sheet metals are welded very well.
6.E7016 is used for hardenable steels when preheat and stress relieving cannot be performed.
7.E7018 which is a low hydrogen iron powder all position electrode can be used for radiograph quality welds.
8.Arc striking with scratch method in the direction of welding is to followed.
9.Use AC to prevent arc blow problem.

10.Use short arc and low current for horizontal position welding.
11.Use whipping motion in the direction of welding for vertical uphill welding.
12.Use constant current power source with 60%duty cycle at maximum current.
13.Transformer sets are useful for all types of structural fabrication.
14.Arc blow problem can be avoided by using AC transformer sets.
15.Motor Generator sets are useful for all types of fabrication in workshops and site work.
16.Inverter sets are highly portable and can be used for all types of fabrication.

Factors to be understood for cooling rate control for weld,HAZ

  1. Preheat and interpass temperature
  2. Material thickness
  3. Heat sinks – presence of chill bars or other ways to drive heat away from the welded part
  4. Heat input from welding – certain process, such as submerged arc welding, can have high enough heat inputs that make preheat not necessary
  5. Use of cooling blankets
  6. Ambient conditions (ambient temperature)
  7. Quenching (air, water, oil, furnace).

Electrode wrong polarity will result in:
– excess spatter and poor penetration
– improper fusion of the electrode
– heavy brownish deposition on the face of the weld metal
– difficulty in manipulation of the arc
– abnormal sound of the arc
– poor weld bead appearance with surface defects and more spatter.

Arc blow control techniques in DC

1. Placing workpiece lead connections as far as possible from the joints to be welded;
2. If back blow is the problem, placing the work- piece connection at the start of welding, and welding toward a heavy tack weld;
3. If forward blow is causing trouble, placing the workpiece connection at the end of the joint to be welded;
4. Positioning the electrode so that the arc force counteracts the arc blow;
5. Using the shortest possible arc consistent with good welding practice to help the arc force coun- teract the arc blow;
6. Reducing the welding current;
7. Welding toward a heavy tack or runoff tab;
8. Using the backstep sequence of welding;
9. If backing is used, welding the entire length of
the backing to each base plate;
10. Changing to alternating current, which may
require a change in electrode classification; and
11. Wrapping the workpiece lead around the work- piece in a direction so that the magnetic field it sets up will counteract the magnetic field causing
the arc blow.

Welding Education and training

 

                                                   Bibliography


List of important reference articles collected from Bibliography sources.

[1] British Standards Institution, 1983 BS 499: Part 1 (Welding Terms and Symbols, Glossary of welding, brazing and thermal cutting).
[2] American Welding Society, 1989 Welding Handbook, vol 1, Welding Technology, 8th edn, Miami, AWS.
[3] International Standards Organisation, ISO 4063, 1998 Welding and allied processes – Nomenclature of processes and reference numbers.
[4] Bay N, 1986 ‘Cold welding’, pts 1–3, Met Constr, 18(6, 8, and 10).
[5] Benn B, 1988 ‘Friction welding of butt joints for high duty applications’, Weld
Met Fabric, August/September, 56.
[6] Nicholas E D and Teale R A, 1988 ‘Friction welding of duplex stainless steel’,
Offshore Technology conf, Houston, TX, 2–5 May 1988.
[7] Nicholas E D, 1982 ‘A friction welding application in the nuclear power industry’,
Weld Inst Res Bull, 23(1).
[8] Essa A A and Bahrani A S 1989 ‘The friction joining of ceramics to metals’,
Proc int conf on the Joining of Materials, JOM-4, Helsingor, Denmark, 19–22
March.
[9] Thomas W M et al. 1984 ‘Feasibility studies into surfacing by friction welding’,
TWI Res Rep, 236, Cambridge: The Welding Institute.
[10] Nicholas D and Watts E, 1990 ‘Friction welding – a sparkling success’, Weld
Inst, Connect, (8) April
[11] Bartle P M, 1983 ‘Diffusion bonding – principles and applications’, Weld Inst
Res Bull, 24(3).
[12] Johnson K I et al. 1979 ‘MIAB welding, principles of the process’, Met Constr
11(11).
[13] Edson D A, 1983 ‘Application of MIAB welding’, Proc Conf Developments and
Innovations for Improved Welding Production, The Welding Institute, Birmingham,
England, 13–15 Sept.
[14] Smith D S, 1989 ‘Control of quality and cost in fabrication of high integrity
pipework systems’, Proc Weldfab Midlands seminar, 25–26 Oct.
[15] 1989 ‘Control of welding – welding procedures, basic welding data, No. 11’,
Weld Metal Fabricat, 57(10).
[16] Salter G R, 1970 ‘Introduction to arc welding economics’, Metal Construct Br
Weld J, June.

[17]Lundin CD, Khan KK. Fundamental Studies of the Metallurgical Causes and Mitigation of Reheat Cracking in 1.25Cr–0.5Mo and 2.25Cr–1Mo Steels. WRC Bulletin No. 409. New York: Welding Research Council; 1996.

[18]Meitzner CF, Pense AW. Stress-relief cracking in low-alloy steel weldments. Weld J 1969;48 (10):431s–440s.

[19]Thomas RD Jr. HAZ cracking in thick sections of austenitic stainless steels, Part 1. Weld J 1984;63 (9):24–32.
[20]ThomasJrRD. HAZ cracking  in thick sections of austenitic stainlesssteels,
Part2.WeldJ 1984;63 (9):355s–368s.

[21]Curran RM, Rankin AW. Welding Type 347 stainless steel for 1100°F turbine operation. Weld J 1955;34 (3):205–213.

[22]Thomas Jr RD, Messler Jr RW. Welding Type 347 Stainless Steel: An Interpretive Report. WRC Bulletin No. 421. New York: Welding Research Council; 1997.

[23]Dupont JN, Lippold JC, Kiser SD. Welding Metallurgy and Weldability of Nickel Base Alloys. Hoboken, NJ: Wiley and Sons, Inc; 2009. p 364–367.

[24]CoeFr.WeldingSteelswithoutHydrogenCracking.Cambridge,Uk:WeldingInstitute;1973.

[25] ISo 17642-3:2005. Destructive tests on welds in metallic materials—Cold cracking tests for weldments—Arc welding processes—Part 3: Externally loaded tests. 1st edn: International organization for Standardization, geneva, Switzerland; 2005.

[26]National Electric Manufacturers Association (NEMA), Electric arc welding power sources, EW1. Rosslyn, Virginia: National Electric Manufacturers Association.

[27]Jackson, C. E. 1973. Fluxes and slags in welding. Welding Research Council Bulletin 190. New York: Weld-
ing Research Council.

[28]Stout, R. D., C. W. Ott, A. W. Pense, D. J. Snyder, B. R.
Somers, and R. E. Somers. 1987. Weldability of
steels. New York: Welding Research Council.

[29]International Institute of Welding. 1984. The Physics of Welding. Ed. J. F. Lancaster. Oxford, U.K.: Pergamon Press.

[30]Salkin, J. T. 1997. Rotating tungsten narrow groove GTAW—a summary of process development, capabilities, and applications. Proceedings of the EWI International Conference on Advances in Weld- ing Technology. Columbus, Ohio: Edison Welding Institute.

[31]Smith, J. S., et al. 1986. A vision-based seam tracker for TIG welding. Computer Technology in Welding. Cambridge, U. K.: The Welding Institute.

[32]Altshuller, B. 1998. A guide to GMA welding of alumi- num. Welding Journal 77(6): 49.

[33]Baujet, V., and C. Charles. 1990. Submarine hull construction using narrow-groove GMAW. Welding Journal 69(8): 31–36.

[34]Bruss, R. A. 1996. Designing GMA welding guns with the welder’s comfort in mind. Welding Journal 75(10): 31–33.

[35]Jonsson, P. G., A. B. Murphy, and J. Szekely. 1995. The influence of oxygen additions on argon-shielded gas metal arc welding processes. Welding Journal 74(2): 48-s–58-s.

[36]Kim, Y. S., and T. W. Eagar. 1993. Metal transfer in pulsed current GMAW. Welding Journal 72(7): 279-s– 287-s.

[37]Kim, Y. S., and T. W. Eagar. 1993. Analysis of metal transfer in gas metal arc welding. Welding Journal 72(6): 269-s–278-s.

[38]Nadeau, F. 1990. Computerized system automates GMA pipe welding. Welding Journal 69(6): 53–59.

[39]Sampath, K., R. S. Green, D.A. Civis, B. E. Williams,
and P. J. Konkol. 1995. Metallurgical model speeds development of GMA welding wire for HSLA steel. Welding Journal 74(12): 69–76.

[40]Kim, Y. S., and T. W. Eagar. 1993. Analysis of metal transfer in gas metal arc welding. Welding Journal 72(6): 269-s–278-s.

[41]Kimura, S., I. Ichihara and Y. Nagai. 1979. Narrow-gap gas metal arc welding process in flat position. Welding Journal 58(7): 44–52.

[42]Mitchie, K., S. Blackman, and T. E. B. Ogunbiyi. 1999. Twin-wire GMAW: process characteristics and applications. Welding Journal 78(5): 31–34

[43]Sadler, H. 1999. A look at the fundamentals of gas metal arc welding. Welding Journal 78(5): 45–47.

[44]Lathabai, S. and R. D. Stout. 1985. Shielding gas and heat input effects on flux cored weld metal properties. WeldingJournal. 64(11):303-s-313-s.

[45]Liu, S. 1998. Arc welding consumables-covered and cored electrodes: a century of evolution. ASM Con- ference Paper: Trends in Welding Research. (6)1998. Materials Park, Ohio: ASM International.


Welding Research

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