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PWL#086 & 086B - Management Duties, Project. Weld. of Steel Nuts, Welding Consumables, Design Change October 01, 2010 |
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| We hope you will find this Letter interesting and useful. Let us know what you think of it. Welding Management Duties, Resistance Projection Welding of Steel Nuts, Welding Consumables, Change in Design, Hardenability, Clinching, Vol.IV of Welding Handbook and more... DON'T USE REPLY to send us your messages! Use Contact Us instead.
and Mid October Bulletin
Please be advised that the Mid Month Bulletin is now integral with the regular PWL publication. You will find it further down, past the end of this PracticaL Welding Letter. Important AnnouncementFor assembling at no cost your own Encyclopedia Online,
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1 - Introduction 2 - Article - Welding Management Duties 3 - How to do it well: Projection welding of steel nuts 4 - Filler Metals: What is new in Welding Consumables? 5 - Online Press: recent Welding related Articles 6 - Terms and Definitions Reminder 7 - Article - Change in Design (CID) 8 - Site Updating: Hardenability, Clinching 9 - Short Items 10 - Explorations: beyond the Welder 11 - Contributions: New Volume of Welding Handbook 12 - Testimonials 13 - Correspondence: a few Comments 14 - Bulletin Board (Sponsored Links)
The present 86th Issue of Practical Welding Letter opens with a few reflections about Welding Management Duties. In a well conducted Company, which employs welding technologies for a considerable part of its productions, the best way for General Management to care to the success of the Enterprise, would be to appoint a knowledgeable Welding Manager capable to exert his/her duties. It is unfortunate when Welding Management either does not exist as such or is unable to operate for the most important economic interests of the company. In that case a huge repository of potential actions suitable to improve the productivity of the enterprise remain unknown and neglected. Nothing can be done without a revolutionary Management attitude. Then we report on a few suggestions specifically referring to resistance projection welding for fastening nuts and similar objects on the surface of industrial assemblies. It appears that little information on the subject is currently available to interested readers. Those in need of keeping up-to-date on consumables for a list of materials and processes, could personally participate in a special Conference where world renowned experts contribute their knowledge and experience. It will be happening shortly. Active persons sparkling with initiatives, may become sometimes frustrated if their ideas on how to improve production are not immediately put to the test. However practical and useful those ideas may be, one should refrain from cutting corners, when it comes to basic rules for applying Changes in Design, including also processing details. It is wise to stick to rigid rules. The new Pages of the Month explain in some depth a very important property of steels, called Hardenability, and also a quite recent joining process called Clinching applicable to mass production of sheet metal parts. Except for those situations where this last process is not applicable because of special appearance requirements, it can be a most economic solution worth of being explored. Readers wanting updated reference information readily available, are strongly advised to procure the new Welding Handbook volume 4, as soon as it is published. AWS Members enjoy a special rebate: don't miss it. The other departments can readily be found at their regular place. Let us have your feedback and comments using the Contact Us Form. Don't use Reply. The references to online resources, assembled in this issue for the Mid Month Bulletin, that follows the regular issue, are devoted to Hardenability, its testing and how to use the results to select suitable steels for any application.
2 - Article - Welding Management Duties While reviewing old issues of this publication, as I do sometimes to discover neglected subjects, I came upon a subject that struck me for its absence. It appears now in the title above. Should we remember that the outstanding professional preparation of the Welding Manager is the most important pillar on which all his/her other achievements are based? The fact is that such preparation cannot be obtained once and for all, but must be continually updated by learning all recent improvements and innovations. This should probably be the first duty. Then, the Welding Manager must be able to get complete and unconditional support from General Management, to obtain the required share of means to best perform the Department assignments, and the freedom to choose how to implement the job. The best way to obtain such a support is to demonstrate time and again that the provisions implemented and his/her initiatives have consistently positive effects on the bottom line of Company operations. Nothing is more convincing that a continuous record of productivity improvements in the daily results records, achieved through the Manager's focused attention, the second duty. To this aim, properly written standard procedures must be set up and followed. Those who specialize in productivity suggest that quite simple means can reach remarkable results: The third duty is to maximize the utilization of limited resources, by freeing welders from all non welding activities, and by letting them always have all they need when they need it, avoiding having them distracted by unproductive chores. The fourth duty consists in the managing the continuing struggle against waste, rework and scrap as well as programmed training and certifications to improve welders' skills and confidence. Equipment maintenance and periodic validation must become routine. A strong personality and the practice of involved leadership, help in confirming the role better than any official title that can be formally bestowed upon the welding manager. Thoughtless General Managers may think unfortunately they will get better results by sparing on the appointment of a welding manager, by letting an engineer with no welding education take the job and do his/her best about it, without even suspecting what the real welding manager duties should be. They will never know what they lose. See also in our website: 3 - How to do it well: Projection welding of steel nuts Some of the most interesting articles explaining basic welding issues are found quite often in short notes intended to provide answers to practical questions proposed by readers. I would like to give here the summary of such a note full of significant details, published at page 16 of the September 2010 issue of the Welding Journal. In his note Donald F. Maatz Jr., member of the AWS Detroit Section Executive Committee and, among others, also of the D8 and D8D Automotive Welding Committees, states that, for many different audiences, when it comes to problems regarding Resistance Welding, "projection welding always tops attendees' list of concerns". The question in cause referred to the lack of published schedules establishing suggested parameters for the projection welding of steel nuts, to be used as a starting specification for the procurement of suitable equipment. Having discussed the need of a suitable schedule for providing the necessary elements for the correct design of adequate equipment and tooling, the author acknowledges the current lack of a "robust set of welding schedule guidelines for the resistance welding of forged or coined projection weld fasteners". It appears that the lacking data are part-specific and as such "not readily available to the welding community". The reason is that too many factors must be accounted for. Among them the materials of fastener and base metal, projection geometry, volume and number, substrate thickness, strength and coating. The author then attempts to provide useful guidelines with the purpose to achieve tentative starting weld schedules to be refined with actual application trials. He suggests that the welding time should be less than what assumed from previous experience with sheet metal projection welding. Then he remarks that the force required should be higher than what one may think, to assure proper contact and adequate forging pressure once the welding current has stopped. He further notes that the welding current may need to be much higher than what presumed to be enough, and then the tooling must be able to carry that higher current and its controls must be suitable for fine tuning. Finally he admonishes that the correct design of the fasteners projections plays an equally important role as the schedule for obtaining quality welds, and he plans to write a future article on this subject. Interested readers are urged to seek the original article given above, where they can find also how to contact this instructive expert author.
4 - Filler Metals: What is new in Welding Consumables? Interested readers can find out by joining the FABTECH in Atlanta, Georgia where, on November 2, one day Conference will cover new gas mixtures and filler metals for materials such as creep strength enhanced ferritic steels, lean duplex stainless, and ferritic/austenitic dissimilar welds. Industries like wind towers will also be covered, as well as numerous processes such as hardfacing, FCAW and metal core. See details at: 5 - Online Press: recent Welding related Articles Five key questions management should ask before repairing by welding How new waterjet technology simplifies the complex Connect - July-August 2010 Lasers will shine in the auto industry The Lincoln Electric Welding School Announces Its 2010 Fourth Quarter Schedule 6 - Terms and Definitions Reminder Backing gas, a shielding gas protective atmosphere, covering the back side of the weld, opposite to the heat source. Cascade sequence is a combined longitudinal and cross sectional sequence in which weld beads are made in overlapping layers, going down in steps (near the root) along the weld. Flowmeter is an instrument designed to measure the flow of a fluid, as regulated by a suitable valve. In welding, it is used for measuring the flow of gases, in units like liter per minute. Guided Bend Test is generally performed by pressing a weld section in a fixture in such a way that the bend radius is specified to achieve a given elongation on its outside surface, considering the thickness. Regulators are pressure control devices used to reduce compressed gas pressure to the required working pressure by means of adjustable pressure valves. Side Bend Test is a test in which the side of a transverse section of a weld is on the convex surface of a specified bend radius. Travel Speed for any welding process is determined by dividing the length covered from start to stop by the time employed. Welding technique consists in the details of a welding procedure that are controlled by the welder or welding operator.
7 - Article - Change in Design (CID) I was recently asked by an inspector, under which circumstances could non destructive inspection be substituted for destructive testing for the purpose of accepting production lots. Although at this point I don't yet know any details relative to the specific case that originated the query, a few considerations can be proposed that should be valid in most of cases. It should be always remembered that engineering design is a complex achievement involving many aspects of knowledge in quite different specializations. So much so that, for important projects, a cautious management should find ways to engage a team of specialists from wherever they can be found, and harmonize their cooperative work. That is because no single person can be expected to be sufficiently versant in all the science and technology involved. Generally speaking, quite often engineering design details are the product of compromise between opposing requirements, (i.e. cost vs. weight) partially sacrificing one to accommodate another. Nevertheless, however difficult might the final decision be, it must be put in the hands of the most expert designer who is endowed with all the responsibility and with the final say. Therefore it is unacceptable to change any of the design and fabrication details without submitting the discussion to a responsible and complete process of examination and evaluation, and without involving the person that accepted to begin with the responsibility by establishing all the design details. Any instance of modification, often called Change in Design (CID), must be the object of a well disciplined and documented process involving the reasons why the present status is deemed inadequate and requiring improvement, why the modification is needed, how it will improve the functionality or the total cost without affecting stability and fabricability, and what advantages it is designed to assure. This process, valid for any engineering change, is even more important when welding is part of the fabrication, mostly because engineers, however expert in their own specific capabilities, may be less alert to subtle metallurgical influences of supposed minor changes. Coming back to the query that originated this note, it must be reminded and accepted that even a change in requirements, in this case on testing or inspection, should be part of the process of change, and fully documented and approved by the highest authority. Especially inspectors should know and insist that only approved changes can be implemented. Any kind of proposed change must be looked at with suspicion, especially when the origin may be a general directive striving to reduce costs. In fact it is quite common to find out that an ill conceived change, instead of saving a negligible sum, finally caused over budget expenses that were not accounted for at the start. Again, as they say, what works acceptably should not be improved... 8 - Site Updating: Hardenability, Clinching The new website Pages of this Month cover two quite different subjects. The importance of this understanding is related to the correct selection of suitable steels for any application, such that, with appropriate heat treatments, the steel will develop the needed mechanical properties in every part of the volume as required. See this new page at Hardenability. Clinching is a mechanical interlocking joining process that uses the properly designed deformation of overlapping sheet metal assemblies to create permanent joints. Mostly applicable for mass productions, it has unique characteristics that may make it the process of choice for assemblies of consumer products. It is worth considering, it may prove invaluable. See this new page at Clinching. To remain updated as new pages are regularly added to the website, please subscribe to the RSS (follow instructions under the NavBar in each page), look at the Site Map, or review periodically the Welding Blog. You are urged to inform your friends of this website: they may benefit from the quite extensive information available and can ask questions that may help them.
9 - Short Items 9.1 - Forgeability is the term used to describe the relative ability of material to deform without fracture, usually at elevated temperature. Also describes the resistance to flow from deformation. 9.2 - Lüders lines are elongated surface markings or depressions in sheet metal, often visible with the unaided eye, caused by inhomogeneous yielding. Also known as Lüders bands or stretcher strains. 9.3 - Mounting is any means by which a specimen may be held during preparation of a section surface for metallographic examination. The specimen can be embedded in plastic or secured mechanically in clamps. 9.4 -Prealloyed Powder is a metallic powder composed of two or more elements that are alloyed in the powder manufacturing process and in which the particles are of the same nominal composition throughout. 9.5 - Rolling-Contact Fatigue is the repeated stressing of a solid surface due to rolling contact between it and another solid surface or surfaces. Continued rolling-contact fatigue of bearing or gear surfaces may result in rolling-contact damage in the form of subsurface fatigue cracks and/or material pitting and spallation. 9.6 - Subgrain is a portion of a crystal or grain, with an orientation slightly different from the orientation of neighboring portions of the same crystal. 10 - Explorations: beyond the Welder The Paradox of Time: Why It Can't Stop, But Must (7 pages) Reverse Combustion: Can CO2 Be Turned Back into Fuel? Reflecting on "The Office of the Future" 40 Years Later Wildfires: A Symptom of Climate Change NASA Sustainability Base 11 - Contributions: New Volume of Welding Handbook On page 93 of the September 2010 issue of The Welding Journal, you may find the page and the order form introducing the new Extensively revised and updated from the eighth edition, this comprehensive volume had more than 50 experts in materials and materials applications assure its accuracy and the currency of its content. It is a great reference source for engineers, educators, welding supervisors and welders. Covers carbon and low alloy steels: high alloy steels; coated steels; tool and die steels; stainless and heat resisting steels; clad and dissimilar materials; surfacing; cast irons; maintenance and repair welding; and underwater welding and cutting. Includes more than 500 tables, charts and photos. Hardbound, 10 chapters, 8-1/2" x 10 1/2", (2010). Offered until December 31, 2010 to AWS Individual Members for only $ 25. The Welding Handbook is a highly recommended reference source for all readers interested in welding. 12 - Testimonials Name: Gilda Lopez Dear Mr. Levi: Thanks in advance for your attention. Gilda Lopez
On Fri Sep 17 11:59:29 2010, the following results were submitted from the
"Form 5" on welding-advisers.com: Name: John Christopher Introduce Your Organization: blackcat engg&construction I am very thankful to you. PWL [is] very helping to me. Again I [am] thanking you to your best services. Regards, 13 - Correspondence: a few Comments 13.1 - A kind reader was asking an interesting question about using nondestructive in place of destructive testing. Unfortunately, instead of using the Contact Us form, he used the Examination Questions This page was intended to assemble Examination Questions proposed by readers who actually met them in real welding examination Course or wrote them up, not for regular questions. The form has no provision for a reply email address. Therefore I was unable to answer to the inquirer. If you see this Comment please send again your question using the Contact form. 13.2 - Although I hope to be providing at least some basic welding information. I still meet with much surprise readers who have not the least idea of what they need and therefore ask such impossible questions as: "I wanna buy some welding machine, but I'm confuse how to select which one the best from supplier welding machine..." Note: no process, no materials, no thickness range, no production capacity, nothing. I am willing to help, but at least clarify what you need...
14 - Bulletin Board 14.1 - Underwater Welding and Inspection Technology 14.2 - ASNT Fall Conf. and Quality Testing Show 14.3 - www.awsweldingbuyersguide.com 14.4 - Previous Issues of Practical Welding Letter are available at the Index of Past Issues of PWL, while the Titles of important Articles published there appear in the page on Welding Topics. 14.5 - Don't miss the SBI! 2.0 Home Page (buildit)
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Bulletin 54 - PWL#086B Keywords: Hardenability, Jominy End Quench Test, Carbon Equivalent, Selection of Steel for given Hardenability, Ideal Diameter, Grossman Method PWL#086B - Resources on Hardenability of Steel, Jominy End Quench Test, ASTM A255 Standard Test Methods for Determining Hardenability, Carbon Equivalent, Selection of Steel for given Hardenability, Ideal Diameter, Grossman Method, Influence of Alloying Elements and more...
Important AnnouncementFor assembling at no cost your own Encyclopedia Online, See a note on Your Opportunity at the beginning of this page, just above the Table of Contents. Introduction The Mid Month Bulletin is now integral with and appended to the regular PWL publication. The subject of this 54th Bulletin is a collection of Online Resources likely to add breadth and depth to the subject presented in our recent page on Hardenability. As the concept is fundamental for the understanding of steel properties and the effect of Heat Treatments, thorough readers would do well to learn at least the essentials of this basic property. Links to the Mid Month Bulletin Pages are listed in the regularly updated page on Welding Resources (Opens a new Window). We urge our readers to Bookmark this page or to subscribe to our Welding Site Blog by clicking on the orange buttons under the NavBar in each Website page.(www.welding-advisers.com) The Index of all previous Issues of the Mid Month Bulletins can be found in the page of Welding Resources. The addresses reported hereafter were live and correct at the time of their publication. There is no guarantee that they will always be so, because they are administered by the sources themselves and are under their control. Note: References to articles or other documents are given here in 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 selected them 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. If the information is important to you as we hope, you may save the selected pages in a suitable folder on your Computer for easy reference. You are welcome to forward this page to those of your friends who may profit of this information. Resources Hardenability Hardenability and Jominy End Quench Test Cast steel: Hardenability of Steels Hardenability testing Hardenability - Examples, applications Hardenability of Steels Hardness vs. Hardenability - There Is A Difference Part 2 - A Discussion on Hardenability and Hardenability Testing The Hardenability of Steel (5 pages) Carbon Equivalent to Assess Hardenability of Steel (9 pages) Hardenability of steels for oil industry Jominy Testing: The Practical Side The Jominy End Quench Test Notes on Hardenability and the Jominy Test Hardenability Index, DI Laboratory 5: The Jominy End-Quench Test (2 pages) Hardenability Technical Publications (13 links to articles) AP3, Hardenability of Steel Hardenability of Steel (2 pages) Metallurgy of Mo in Alloy Steel & Iron Influence of Chemical Composition and Austenitizing Temperature on Boron in steel as an alloying element The Effect of Boron in Ductile Iron The Science and Engineering of Materials, 4th Ed. Selection method of steel grade with required hardenability Experiment #8 - Hardenability of Steels (6 pages) The effect of nitrogen and vanadium on hardenability [...] (6 pages) Lecture 8: Alloy Steels - MMat 380 (Presentation - 25 pages - 50 frames) Fundamentals of Heat Treating: Ideal Diameter Applications of Hardenability (Presentation - 10 frames) Effect of Chemical Elements in Steel
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