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PWL#078 - Understanding Differences between Welding Education and Training, Braze-Welding of Steel February 01, 2010 |
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| We hope you will find this Letter interesting and useful. Let us know what you think of it. PWL#078 - Understanding Differences between Welding Education and Training, Braze-Welding of Steel, Preventing Consumables from being Hydrogen Sources, Computational Weld Mechanics, Managing Welding, Electroslag Welding, Interview with Paul Ipolito and more...
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1 - Introduction 2 - Article - Welding Education vs. Training 3 - How to do it well: Braze welding of steel 4 - Preventing Consumables from being Hydrogen Sources 5 - Online Press: recent Welding related Articles 6 - Terms and Definitions Reminder 7 - Article - Computational Weld Mechanics 8 - Site Updating: Managing Welding, Electroslag Welding 9 - Short Items 10 - Explorations: beyond the Welder 11 - Contributions: Interview with Paul Ipolito 12 - Testimonials 13 - Correspondence: a few Comments 14 - Bulletin Board
This publication brings to the readers practical answers to welding problems in an informal setting designed to be helpful and informative. You are urged to pass-along this publication to your friends, if you like it, and if you want to help them. If you received this from a friend and if you like what you read, please subscribe free of charge and you will also receive a bonus book on Practical HARDNESS TESTING Made Simple. Note: References to articles or other documents are given here in one of two forms. If the links are "live" (usually underlined or otherwise highlighted) they are operated with a click of the mouse. If they are URL's (Uniform Resource Locator), which is the analogue of an address, they begin with "http://..." or "www.". These are not live and must be copied and pasted entirely into the browser (after having been selected with the mouse or otherwise). If they are long they may be displayed in two or more lines. In that case one has to care that the URL be copied completely in a single line without any space, and Enter. (Sponsored Links) 1 - Introduction This new 78th Issue of Practical Welding Letter opens with an Article on Welding Education vs. Training written specially for this publication by Professor Yoni Adonyi, Ph.D., P. E., Omer Blodgett Chair of Welding and Materials Joining Engineering at LeTourneau University, Longview, Tex. The opportunity of learning from this and, hopefully, from further valuable contributions he kindly agreed to send us, is highly appreciated and should be welcomed by our audience in that it makes this publication even more interesting and useful. Follows a short note with a few tips written to help a student trying to make an acceptable braze-welding on a specimen for passing a test and starting the next training level. For the section on Consumables a primer is given on precautions needed to prevent the introduction of Hydrogen with the Consumables, when welding steels susceptible to Hydrogen Embrittlement. Computational Weld Mechanics is an active developing technology aimed at providing forecasts as to the behavior of complex structures upon welding, by examining the virtual numerical results of finite elements exercises on parallel proposals of different physical techniques, with the purpose of selecting the most appropriate before making costly tests. The interview published here is with Paul Ipolito, a long time friend and collaborator who kindly submitted a summary of his personal experience and a few suggestions to new welders planning their own careers. In the Website Update section two new pages are introduced, the first dealing with practical aspects of Managing Welding Operations, the second with a mature welding process, that using Electroslag for Welding, useful and highly cost effective in a few niches of application. Other sections appear at usual at their place. Readers are invited to let us have their comments and feedback, as well as contributions of personal experience or suggestion of new subjects that might interest our audience. Use the Contact Us form to let us have your comments and feedback. (Don't use Replay).
2 - Article - Welding Education vs. Training
Understanding Differences between |
| Figure 1. Welder/operator training involves observation, practice, testing and results in an acquired skill for a trade. Good eye-hand coordination and steady movements are required in a hazardous environment. |
The associated concept of ACCREDITATION can be traced back to the Latin root word "accredere", which means to give credence to, and comes from the combination of the words 'ad' and 'credere' (to believe, a set of fundamental beliefs). In other words, accreditation means to give official authorization, to provide with credentials. For educational institutions, this means to maintain standards that qualify graduates for admission to higher institutions of professional practice (Webster's).
Finally, the word CERTIFICATION comes from the Latin "certus", or certain, and means to attest authoritatively or to attest as being true or as meeting a standard. Another interpretation is to testify to the truth or genuineness of something – applies to a written statement, carrying signature and seal.
The implications of the above differences are significant and need to be discussed candidly to avoid inadequate transfer of knowledge and applications that can result in costly repairs and sometime, catastrophic failures. The purpose of this paper is to clarify the differences between education and training, as applied to the welding/materials joining industry and the role of professional organizations in correctly promoting welding to future generations.
DISCUSSION
If we put together the above four concepts discussed in the Background section, Accreditation is concerned with an Educational belief system, while Certification simply attests conformance with specific Training outcomes. One example from the US welding industry is ABET accreditation of a BSc degree in Materials Joining Engineering at LeTourneau University (since 1953) versus Certification of American Welding Engineers from the American Welding Society. Another famous program is the Welding Engineering Education at The Ohio State University (since 1946). The newest Engineering program is about to be launched in 2010 at Liberty University, all well structured accreditable programs.
As the Background Section showed, Education is more inclusive (or can include Training), while the opposite is not true. However, the word Education is often misused to describe Training, simply because it sounds and sells better. One such example is the "Education" committee of the AWS that does not include any educators beyond 2-yr Associate Degree College level and certainly deals with selling Training activities that are Certified (see Certified Welding Inspector CWI Program). While these are commendable programs, they are clearly not Educational in nature and thus they tend to abuse the word Education.
Similarly, several large welding companies "declared" that they offer training under "ESAB University" and other unofficial names that imply that they offer Higher Education level courses. This can be deceiving and unhealthy for the welding industry at large, as trainees typically think they know more about welding fundamentals than they really do. What is especially dangerous is that Training programs do not have to be periodically re-certified as academic programs have to be re-accredited every 4-6 years. Once a Training program is put in place, it can be run indefinitely, in spite of advances in science and technology.
On the Education side, however, the Accreditation Board for Engineering and Technology (ABET), makes sure that each program has a system in place to provide ongoing quality education. The new ABET 2000 criteria are similar to ISO 9000 Quality Improvement Programs, where the main objectives and goals are defined and Engineering graduate outcomes are constantly measured by surveying stakeholders such as students, alumni and employers. After ABET approves this continuous improvement cycle that also includes sub-sections on curriculum, faculty, labs and other facilities, as well as institutional support, they return on a 4-6 years cycle to verify compliance and assess progress.
| Figure 2. Welding Engineers (such as Mrs. Anna Biggs, Class of 2009, shown with the author at graduation) have to know design, metallurgy, processes and nondestructive testing. They have to analyze data, validate hypotheses, optimize costs while ensuring safety, communicate effectively and work well in teams. |
In conclusion, this opinion piece clarifies some of the differences between Education and Training, as well as Accreditation vs. Certification, especially when misapplied by some in the US Welding industry. Potential dangers of missing the above concepts were emphasized and proper dissemination of this information could eventually avoid catastrophic failures.
Disclaimer: This is a collection of personal views and opinions on the subject by the author, based on his individual experiences in 33 years in the business practiced in three countries (Romania, Israel and the USA) and several industries (pressure vessel, aerospace, primary metals, heavy manufacturing, as well as academia). The author teaches at LeTourneau University, Longview, TX.
I am indebted to the kindness of Professor Adonyi, who generously agreed to share with our audience from his experience and views. I hope we will see more of his instructive contributions in future issues of this publication.
E.L.
3 - How to do it well: Braze-Welding of steel
Q: We have to complete various tests on "coupons" fitted together. On 2 pieces of very thin 1/16" metal, I sheared them off at 8 inch lengths (3" wide) and went into the grinding room and ground everything that the braze-weld would touch. I tacked both outer sides (which looked excellent) and then proceeded to braze-weld. I had a thin layer of bronze on the top side, no penetration and then after 6 inches the whole length of the weld cracked right down the middle of the weld.
A: The above description does not mention essential steps of the process. Both sides of the joint should be generously covered with flux before even starting to braze-weld. The groove gap between the parallel coupons should be between 1/32 and 1/16".
The oxyacetylene flame should be slightly oxidizing as explained in the following ESAB Handbook-Braze Welding page at
http://www.esabna.com/euweb/oxy_handbook/589oxy14_1.htm
and then use the right arrow to see the following pages.
Finding the right base metal temperature for successful wetting (ESAB calls this "tinning") of the base metal by the brass filler metal may be the most tricky part of the exercise. They suggest to try a bead on plate for getting the feeling.
To obtain penetration of the filler metal in the joint one should have the bottom side of the joint reachable by the flame, and then alternatively manipulate the torch from both sides without overheating the base metal.
Trying to do this again and again is the only way to reach the needed skill.
4 - Preventing Consumables from being Hydrogen Sources
The Consumables used for welding Steels suspected of being prone to Hydrogen Embrittlement, are one of the possible sources of this gas, dangerous to the soundness of this work.
Manufacturers exert their utmost diligence in providing low hydrogen consumables with the lowest and controlled level of moisture, at least for those intended for use on steels where there may be danger of hydrogen embrittlement.
Storing conditions are then most important in preserving the low moisture. Therefore storerooms should be dry and warmed up at all times. Strict discipline in moving and handling consumables should be clearly stated in internal documents and enforced by suitable supervision.
Therefore, together with other precautions, consumables must be scrutinized for making sure that they are not victim of careless handling.
In particular the principal sources of hydrogen to be removed from welding consumables are:
- Moisture in the cover of manual stick electrodes, in Submerged Arc Welding (SAW) flux or in the core of flux cored wires,
- Any other compound containing Hydrogen in coatings or fluxes,
- Dirt, oil or grease on the surface of welding filler wires,
- Rust (hydrated oxide) on welding filler wires.
Moisture may be present in different forms, either as absorbed water vapor, or more or less tightly combined with the substances included in the shielding atmosphere generating materials. The treatments designed to remove moisture must be done at a sufficiently high temperature to drive out the most strongly bound combined water of crystallization.
Dirt or lubricants and other materials used in drawing compounds used during manufacturing, from which hydrogen could be generated, must be removed by suitable cleaning methods.
Under heat from the welding arc the sources may break down to liberate hydrogen ready to be picked up in the weld. A small contribution can be supplied by the humidity of ambient air surrounding the welding process, in spite of the shielding.
The amount of hydrogen that can be extracted in the laboratory from a quantity of affected consumables is called the potential hydrogen level of that batch of material. This designation indicates that not all the available hydrogen finds its way into the weld.
However to characterize the level of hydrogen introduced by a given consumable using a specific welding process, laboratory measurements are conducted on a given welded specimen, according to standard procedures.
These determinations help in classifying the consumables, as provided by suppliers or as dryed up as specified by manufacturers, according to accepted convention. The weld hydrogen is considered very low if less than 5 milliliter per 100 gram of deposited metal, low between 5 and 10, medium between 10 and 15.
The measured values help by providing an entry point into the methods used for guidance on the welding conditions to be respected for avoiding hydrogen cracking.
For a more complete review of this problem see our page on Hydrogen Embrittlement.
5 - Online Press: recent Welding related Articles and Videos
What's the ideal laser process for a particular application?
Optoiq.
The Evolution of TIG
https://www.welding-advisers.com/support-files/tiptig.pdf
GMAW guns and consumables
http://www.thefabricator.com/article/arcwelding/gmaw-guns-and-consumables
Holding back the hydrogen
http://www.thefabricator.com/article/arcwelding/holding-back-the-hydrogen
Millermatic Reach & Dual Feed MIG Welding at Fabtech 2009 (video)
https://www.youtube.com/watch?v=_0SWc3ho74E
Welding Copper (video)
http://www.facebook.com/video/video.php?v=140922665252
6 - Terms and Definitions Reminder
Depth of Bevel is the perpendicular distance from the base metal surface to the root edge (if the bevel reaches the opposite surface or the edge of an opposite bevel) or to the root face (the portion of the root perpendicular to the base metal surface)
Flame Propagation Rate is the speed at which a flame runs across a mixture of gases.
Iron Soldering uses a heated tool to bring heat to the joints to be soldered.
Moving Shoe or Dam is a backing device for containing the molten weld metal. During welding, this type of shoe can slide along the joint.
Paste Brazing Filler Metal is a fine mixture of ingredients, metal powder and flux or carrier, to be deposited near a joint for brazing.
Postflow Time is the duration of a continuing flow of shielding gas after the welding arc is extinguished.
Single Square Groove weld is done by welding a square groove joint from one side only.
Temporary Weld is used to attach an element to a weldment as an aid for assembling, handling, moving, shipping or working.
7 - Article - Computational Weld Mechanics
A recent article, published in the January 2010 issue of the Welding Journal at page 40, briefly describes a few success stories relative to the application of this quite recent computational simulation technique, to predict the outcome of different joint designs and alternative welding processes on specific weld joint configurations.
The examples reported refer to:
- Minimizing Welding Distortion in a Heavy Section Joint
- Rapid Prediction of Welding Distortion in Large Scale Assemblies
- Reduction of Welding-Induced Distortion in an Electron Beam Welded Gear Wheel.
Among the results sought by the parallel simulations are the state of distortion, the development of definite microstructures, the map of residual stresses, hardness distribution in weld metal and heat affected zones.
The larger diffusion of this computational tool is still awaiting the development of more complete software programs capable of investigating additional configurations and materials.
It appears that the knowledge and practice of the technology is already available at research centers and institutes who would presumably be ready to work on contracts funded by interested organizations for virtual solving of their specific practical problems.
The American Welding Society (AWS) Committee A9, promoted an initial survey which resulted in the decision to focus on developing a recommended practice for Computational Weld Mechanics of fusion welding of metallic materials to predict residual stress and distortion.
The article authors declare that "at this time CWM is rapidly rising from an emerging technology to one approaching maturity".
Interested readers are urged to seek the article mentioned above.
At least two recent books on Computational Welding Mechanics show up in a Google search.
8 - Site Updating: Managing Welding, Electroslag Welding
The Pages of this Month deal with two unrelated subjects. Managing Welding should be a mature profession studied not only by welding specialists but also by Management experts who generally cater to the needs of all organizations.
In fact this is not always the case. In the words of Jack R. Barckhoff, PE, founder and CEO of Barckhoff Welding Management Corp., a 30-year-old management consulting firm:
"Convincing top management to take action necessary to improve their welding operations can often be challenging. This is often surprising given that they have overall responsibility and are held accountable for their company's bottom line profits."
Therefore it seems important to expose a few facts intended to improve the situations where all decisions are left to the workers who, however skilled and dedicated, may not be able to provide adequate management, with results reflecting in the bottom line.
Click on Managing Welding to see the new page.
The other page describes one of the most cost effective welding processes that can be used, if applicable, to join heavy sections. Once certain difficulties on low impact properties were overcome, the process is now approved also for demanding applications.
Click on Electroslag Welding to read the new page.
Keep informed on new pages either by subscribing to RSS feed (follow instructions under the Navigation column in every page of the www.welding-advisers.com website) or by visiting the regularly updated Site Map.
Write us your comments by using the Contact Us form. Don't use Reply to this newsletter, because that sends it back to me, obviously useless.
9 - Short Items
9.1 - Reliability is a quantitative measure of the ability of a product or service to fulfill its intended function under stated conditions for a specified period of time.
9.2 - Superconductivity is the property of many metals, alloys, compounds, oxides, and organic materials at low temperatures where their electrical resistivity vanishes and they become strongly diamagnetic.
9.3 - Surface Hardening is a generic term describing several processes applicable to a suitable ferrous alloy that produces, by quench hardening, a surface layer that is harder or more wear resistant than the core. Induction hardening and Flame hardening are produced by preferential heating of the external surface followed by sudden quench. Other processes are based on diffusion enrichment of the surface with carbon and/or nitrogen.
9.4 - Wire Drawing consists in pulling wire through a die to reduce its cross section, to impart the required cross section shape and tolerance, and to control mechanical properties.
9.5 - X-Ray is called a penetrating electromagnetic radiation, usually generated by accelerating electrons to high velocity and suddenly stopping them by collision with a solid body.
Another way of producing X-Rays, to be possibly developed for economic medical equipment, is illustrated in the following:
Sticky Tape X-Rays (Video)
http://www.nature.com/nature/videoarchive/x-rays/
9.5 - Yield Strength is the stress at which a material exhibits, in a standard tensile test, a specified deviation from proportionality between stress and strain. For many materials, particularly metals, a conventional offset of 0.2% is used for reporting mechanical properties.
10 - Explorations: beyond the Welder
A "Teaching" Moment in Science Education
http://www.sa-decade2.com/education/science-education.html
The Violent, Mysterious Dynamics of Star Formation
http://discovermagazine.com/2009/feb/26-violent-mysterious-dynamics-of-star-formation
Technologies for Public Safety and Security
http://www.nist.gov/public_affairs/factsheet/homeland.htm
General Motors - Sequal - Hydrogen Fuel Cell Car (Video)
https://www.youtube.com/watch?v=Obs2tAq57j8&NR=1
Single shot induction hardening(Video)
https://www.youtube.com/watch?v=stk7XwLtNMA
11 - Contributions: Interview with Paul Ipolito
Q: What did appeal to you when you first considered welding as your Career?
A: I'm an "accidental" welder. See below.
Q: How did you start your welding Career?
A: I started by trying to sign up for an auto body repair course at a local vocational night school. All classes were full except welding. (Perhaps that was a hint!).
Q: Did you plan to achieve definite Career milestones in a given timeframe?
A: I did have definite milestones in mind, but no timeframe. As I learned of different opportunities in the welding field I pursued them.
Q: In which field of welding are you active?
A: Welding Engineering and Quality Assurance.
Q: Which were your major achievements during your Career in welding?
A: AAS degree in Welding Technology, Passing the CWI Test in 1979 using ASME IX and VIII as my (untabbed) reference material. I will never forget the looks on the faces of the folks using the API 1104 code book.
[Note: for better understanding, the following clarification was offered:]
If you chose the ASME Code for your reference code during the early versions of the CWI test, you were required to bring Section 8 and 9 which consisted of about 1,000 pages of information. The API 1104 Code was about 100 pages. The test was timed. I had 1,000 pages of untabbed reference material I needed to search for answers. The rest of the people in the room had 100 tabbed pages to search. I felt proud that I took the toughest route and passed the first time.
Q: Which of your achievements procured to you the highest satisfaction?
A: CWI.
Q: Which challenges did you find hard to overcome?
A: Working as a Welding Engineer and thinking I knew a lot more than the
welders. Big mistake!
Q: What did help you in persisting and overcoming the difficulties?
A: Learning the hard way to be able to work with all types of people in
welding.
Q: Which is the most important lesson you would like to transmit to young welders?
A: Take it seriously and continue your education. Never stop learning.
Q: Which goals should a young welder aim to reach?
A: Only the young welders can answer that question. I have seen too many over the years that are satisfied with what they learned and making no attempt to upgrade skills and/or knowledge.
Q: Do you foresee interesting developments likely to change the welding profession?
A: Not on a large scale. How many pounds of stick electrodes were sold in 2009? People like being comfortable.
Q: How would you invite young people to consider welding as their Career?
A: I would tell young folks that it is not a static career. You can go as far as you want to if you have the desire and a plan.
Thanks to Paul Ipolito for his nice contribution. Best greetings.
Many young welders could take example and encouragement to seek challenges and finding how to overcome the difficulties.
Readers who offered to write their interview but did not yet send it to us, are reminded to do so now.
12 - Testimonials
From: Chris Holmes
E-mail address: removed for security
To: Welding Advisers
Date: 14 Jan 2010, 01:26:36 AM
Subject: RE: A & V
Many thanks for your reply.
Best Regards,
Chris Holmes
From: John Ireton
E-mail address: removed for security
To: Welding Advisers
Date: 21 Jan 2010, 12:48:38 PM
Subject: RE:1045
Elia,
Thank you for the prompt answer on the 1045 to 1018.[...]
John Ireton
13 - Correspondence: a few Comments
13.1 - It is hard to believe.
I am still being asked what is "the most successful welding process for stainless steel".
This question is at fault at least in two aspects.
First: Stainless is not a definite material. There are at least five different classes of stainless steel, (Austenitic, Ferritic, Martensitic, Precipitation Hardenable, and one more modern class, called Duplex, with mixed compositions and properties) each one with specific compositions, properties, applications, welding procedures and requirements. See
https://www.welding-advisers.com/Welding-stainless.html
Second: There is not such a thing as the most successful welding process for any material. Depending on application, joint types, dimensions, design and mechanical properties requirements, processes, equipment, consumables, and workforce available, production environment, time frame and costs affordable, there may be more than one satisfactory procedures from which the least expensive can usually be selected.
13.2 - Another unanswerable question is the following.
"We need to check/test the strength of [...] parts and equipment after complete welding. So, we need to buy a machine for testing welding."
This question too is at fault.
Supposing that the question refers to a universal tensile testing machine, one should know at least for which material and maximum strength the tests are required. If however the requirement is for testing welding for hardness, resistance to bending, to fatigue, to impact, to fracture toughness or to creep and rupture at elevated temperature, then the information is clearly insufficient.
14 - Bulletin Board
14.1 - WESTEC 2010.
March 23-25, 2010, Los Angeles Convention Center
www.westeconline.com
14.2 - GAWDA Spring Management Conf.
April 18-20, 2010 - Hyatt Regency, Chicago, Ill.
www.gawda.org
14.3 - SMST 2010:
The International Conference on Shape Memory and Superelastic Technologies
May 16-20, 2010 - Asilomar Conference Center - Pacific Grove, California USA
http://asmcommunity.asminternational.org/content/Events/smst10/default.jsp
14.4 - International Symposium on Surface Hardening of Corrosion-Resistant Alloys
May 25-26, 2010 - Case Western Reserve University - Cleveland, Ohio
http://hts.asminternational.org/content/Events/surfacehardening/index.jsp
To see the Titles of articles published in previous issues of Practical Welding Letter, click on Welding Topics
For the complete list and links to the previous issues, click on
Index of Past Issues of PWL.
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