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PWL#168, Safe Robotic Welding, Planning for new automation, Nuts welding to HSLA, TS success story
August 01, 2017
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Practical Welding Letter No. 168
August 2017

PWL#168, Making the Standards for Safe Robotic Welding, Reducing financial risk when implementing automation, Resistance Projection Welding Nuts to High-Strength Low Alloy (HSLA) Steel, Thermal Spray Success Story, How 80/20 rules metal fabrication, Beyond the Welder and much more...

August 2017 - Practical Welding Letter - Issue No.168

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1 - Introduction

2 - Article - Making the Standards for Safe Robotic Welding

3 - How to do it well: Reducing risk when implementing automation

4 - Resistance Welding Nuts to High-Strength Low Alloy (HSLA) Steel

5 - Online Press: recent Welding related Articles

6 - Terms and Definitions Reminder

7 - Article: Thermal Spray Success Story

8 - Site Updating: Thermal Spray

9 - Short Items

10 - Explorations: beyond the Welder

11 - Contributions: How 80/20 rules metal fabrication

12 - Testimonials

13 - Correspondence: a few Comments

14 - Bulletin Board

1 - Introduction

Is there a chance that this 168th Issue of Practical Welding letter be read at all? We are in the thick of vacation season, and we too will soon take a few days off. Anyhow here it is, to be read, saved or ignored.

The first article reported (2) deals with the most important issue of safety in a robotic environment. While we were speaking, (Dum loquimur) the members of the AWS technical Committee D16 were busy providing the essential requirements to avoiding injuries to personnel caught between the moving parts of any robotic cell. We should all be grateful for their work.

Then we move on to another risk, financial this time (3), if moving to automation through the use of robotic equipment is done without adequate preparation. A few recommendation proposed by expert people who saw both success and failure in this area should be handy to those still unsure on the best way to implement their program.

Resistance welding nuts may need special attention (4) if HSLA is involved instead of regular mild steel. Nothing less than a development program as suggested may be needed, after having implemented the necessary upgrade of equipment.

A success story follows (7) on how thermal spray of tungsten carbide gained many extra months of active work for tools subject to hard work involving severe wear. Finding exactly what is needed may be difficult, but only by arduous trying and testing can one reach favorable results.

The old 80/20 rule may give positive results (11) even in metal fabrication, if applied by looking seriously for the relative success of each job and by concentrating the best efforts towards the implementations providing the highest gains. An article explains how specialized software helped a certain company to better understand the relative value of certain jobs.

The other regular items can be found where they usually are. We hope you all enjoy pleasant and refreshing vacation time. Comments and feedback are always welcome. Please use the Contact Us Form.

2 - Article - Making the Standards for Safe Robotic Welding

Weld. Jnl. Cover July 2017

Is working with welding robots safe from dangers to humans? It should be, if a strict discipline to follow the rules, established by applicable Standards, can be enforced on all who may interact with the machines.

A new article, published at page 34 of the July 2017 issue of the Welding Journal, describes the work of AWS technical Committee D16, already active for more than 30 years. Its endeavors concentrate on the development, creation and publication of recommended practices and standards.

Starting from 1991, the need was perceived for robotic arc welding safety standards to tackle all circumstances connected with hazards of robot systems producing welded components.

The authors report on a disagreement within the robotic industry, on safety standards of general nature, versus those developed with a narrow focus on the specific technology of given applications.

The members of the D16 Committee believe that specific standards provide the highest benefit to users.

Much work still waits to be done to produce safety standards concerning robotic welding for the processes GTAW, Resistance, laser and friction stir welding. The Committee is quite busy but has no intention of slowing down or avoid impending obligations.

Interested readers are invited to seek the original article.

3 - Reducing investment risk when implementing automation

Weld. Jnl. Cover July 2017

While investing in welding robots can reduce the struggle to find expert welders and improve productivity and quality, one can reduce the economic risks by adopting suggested steps.

These are listed in a recent article published at page 44 in the July 2017 issue of the Welding Journal by an automation product specialist.

Start small is the first suggestion. It makes sense that the larger the parts the more complex will be the robot to be selected for performing the job. Moreover the variation in tolerances stack up in a large part, multiplying the difficulties.

By heeding this advice the costs incurred in correcting surfacing problems like fixturing issues and extra programming are less expensive.

The second step recommends to start with simple weld joints and parts. The easiest to weld successfully are fillet and basic lap joints. This selection helps control the repeatability of the joint within one half the wire diameter.

An essential part of more complex joints, root opening, recommended at one half of the thinnest member thickness, may be difficult to maintain, with the limited experience of a starting up operation.

Repeatable and accurate upstream fabrication is an essential key to success. Therefore great efforts must be dedicated to obtain parts perfectly fitting the fixtures. Also timing must be kept under control to optimize workflow.

A rule of thumb is proposed in the above exposition: to maximize the return on capital investment, a robotic welding system should produce roughly a 3-to-1 gain over what a human welding operator can achieve. Can our expert readers confirm that this goal can be met?

The fourth recommendation refers to speed. The author considers a mistake operating the robotic welding system at full speed from start. Trying first slowly, at about a quarter speed, permits to check misalignments or crashing the robot against part or fixture. Increasing speed gradually allows to correct inconsistencies before running at full speed.

Lastly the author reminds that part of the investment in automation should include the right people with complete training, given by the original equipment manufacturer, to support the system.

He is confident that, by following the recommendations, one can maximize the investment, ensuring the success of automated welding system from start to finish.

Interested readers are urged to seek the original article, whose author can be contacted if necessary.

4 - Resistance Welding Nuts to High-Strength Low Alloy (HSLA) Steel

Weld. Jnl. Cover July 2017

Answering to a puzzled inquirer who found the hard way that old schedules were failing specification requirements, the three experts signing the Resistance Welding Manufacturing Alliance (RMWA) Q&A column at page 26 of the July 2017 of the Welding Journal comment that the difficulties stem from extra hardness and inconsistent surface condition of the stronger newer material.

They point out that when the strength of sheet metal exceeds 700 MPa, and may reach 1200 MPa, it is difficult to forge the projections of nuts into the sheet metal without expulsion and inconsistent weld strength.

The three authors recommend undertaking a thorough research and development procedure to identify and optimize the three most important variables in resistance welding: weld force (tip pressure), weld current (secondary amperage), and weld time (the duration of current flow).

A combination of high weld current and short weld time is recommended because the intense heat at the projections allows the welding/forging process to take place fast before the projections are "blown out."

A fast follow up device is considered essential to the success of the operation.

The recommended procedure of establishing a proper weld lobe, that is a window of suitable parameters likely to provide acceptable results, is spelled out in seven steps clearly described and demonstrated.

Follows in the article a discussion of different types of power supply, (AC, MFDC,CD) with their characteristics and description, and a reminder of safety precautions to be implemented.

Interested readers who may confront similar problems, are warmly invited to seek the original article, and to contact the authors for further information if necessary.

5 - Online Press: recent Welding related Articles

How joining a startup can help youngsters shape their career

Hot nanotubes help strengthen 3D printed thermoplastics in novel welding process strengthen-3d-printed-thermoplastics-in-novel-welding-process.html

Cloning Master Welders with Robotics

At 25, EWF’s qualification system addresses the challenges of Industry 4.0

2016 Was a Good Year for Lasers; 2017 Looks Even Better

Those with an interest in Failure Analysis may find useful information in the recent Bulletin of the Electronic Device Failure Analysis Society, of May 2017, Volume 19, Issue 2 available from

Although most of the articles are too specialized maybe, some address generalized problems likely to be well received by curious readers.

6 - Terms and Definitions Reminder

Refractory Metals, by convention, are those with a melting point greater than 2000 °C (3,630 °F).

Slag is a nonmetallic product resulting from the mutual dissolution of flux and nonmetallic impurities in smelting, refining, and certain welding operations. In steelmaking operations, the slag serves to protect the molten metal from the air and to extract certain impurities.

Tack Weld is made provisionally to hold components in alignment until final welds are made.

Usability is a measure of the relative ease of application of a welding filler metal to make a sound weld.

Vacuum Melting is melting in a vacuum furnace to prevent contamination from air and to remove gases already dissolved in the metal. The solidification can also be carried out in a vacuum or at low pressure.

Wash Pass is a nonstandard term used to mean a cosmetic weld pass or a cover pass.

X-ray topography is a technique that comprises topography and x-ray diffraction. The term topography refers to a detailed description and mapping of physical (surface) features in a region. In the context of the x-ray diffraction, topographic methods are used to survey the lattice structure and imperfections in crystalline materials.

Yield is the evidence of plastic deformation in structural materials. Also known as plastic flow or creep.

7 - Article: Thermal Spray Success Story

iTSSe Cover MayJune 2017

Blow molding and plastic injection molding technologies are used to mass produce parts made of plastics like glass filled nylon material. Unprotected tooling components made of wear resistant metals suffered from wear, producing nonconforming parts and production disruption.

Applying by the high velocity oxy-fuel (HVOF) process a thin layer (0.010 in.) of tungsten carbide and then grinding to the required surface finish, increased tooling duration from 8 months to more than 23 months.

A short article published in the iTSSe newsletter mentioned already in the last PWL issue provides all the details.

Interested readers can obtain the publication from ASM International.

On another subject, please be informed that

SPRAYTIME - Second Quarter 2017 / Volume 24 - published by the International Thermal Spray Association, a standing Committee of the Ameerican Welding Society,

is available for download from:

Recommended at page 14 is an article on:
The Basics of Thermal Spray Safety

Blow mold head tooling

Blow mold head tooling (die and pin) coated with a tungsten carbide/cobalt matrix after 19 months in service.

[From iTSSe May-June 2017 - Vol. 12 - Issue 2 - page 10 (44)]

8 - Site Updating: Thermal Spray

The updated website page contains, among other editing, a reference to this PWL#168, specifically to column (7) reminding a thermal spray success story, and the availability of a new brochure from ITSA (International Thermal Spray Association).

The revised page can be read by clicking on Thermal Spray.

It is hoped that people working on these processes are alert to all information regarding safety, like that reported in the publication indicated above.

9 - Short Items

9.1 - Gouging is, in welding practice, the forming of a bevel or groove by material removal.

9.2 - Heat-affected zone (HAZ) craking, is that appearing in the portion of the base metal that was not melted during brazing, cutting, or welding, but whose microstructure and mechanical properties were altered by the heat.

9.3 - Ion Implantation is the process of modifying the physical or chemical properties of the near surface of a solid (target) by embedding appropriate atoms into it from a beam of ionized particles.

9.4 - Jominy test or end-quench hardenability test is a laboratory procedure for determining the hardenability of a steel or other ferrous alloy; widely referred to as the Jominy test. Hardenability is determined by heating a standard specimen above the upper critical temperature, placing the hot specimen in a fixture so that a stream of cold water impinges on one end, and, after cooling to room temperature is completed, measuring the hardness near the surface of the specimen at regularly spaced intervals along its length. The data are normally plotted as hardness versus distance from the quenched end.

9.5 - Knurling means impressing a design into a metallic surface, usually by means of small, hard rollers that carry the corresponding design on their surfaces.

9.6 - Leak Testing is a nondestructive test for determining the escape or entry of fluids (liquids or gases) from pressurized or into evacuated components or systems intended to hold them. Leak testing systems, which employ a variety of gas detectors, are used for locating (detecting and pinpointing) leaks, determining the rate of leakage from one leak or from a system, or monitoring for leakage.

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10 - Explorations: beyond the Welder

Novel Gene Therapy for Leukemia Clears FDA Panel

LHC Physicists Unveil a Charming New Particle

North Korea Missile Test: Best Response May Be Surprisingly Low- Tech

Tripping on Peyote in Navajo Nation

Students are Better Off without a Laptop in the Classroom

11 - Contributions: How 80/20 rules metal fabrication

A recent article with the above title from

stresses how important it is for fabricators to "maximize some results, like sales or profits, by systematically deploying available resources only to the drivers that have the most impact".

What exactly is the high-impact 20 percent? To answer this question, a company first needed to uncover the current state, including the true velocity of jobs on the manufacturing floor: what moved quickly and what didn't. Three years ago the firm upgraded its enterprise resource planning system (software) that gives everyone that kind of visibility.

The company had built its processes around certain quality requirements that were appreciated by their customers. Cheaper solutions were not the answer.

In an interview the general manager of that company said: "The bottom line is this: Customers like engaging in transactions with people they enjoy and whom they trust. You maximize their dollar and add value, because you bring things to the table that your competition isn't doing."

This wisdom is probably applicable to the majority of industrial fabrication enterprises: it may be rewarding to look for ways to implement the lesson of this simple rule.

Readers may check the article at the above link.

12 - Testimonials

On Sun Jun 25 01:07:40 2017, the following results were submitted from the "Form 5" on

E-Mail Address: removed for security
Country: India
Organization: L&T
Details: [...].
So kindly tell what impact will it have in welding properties and can we use it?

13 - Correspondence: a few Comments

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14 - Bulletin Board

14.1 - Weld Repair Conference
Aug 8, 2017 - Aug 9, 2017
Hilton Portland & Executive Tower, Portland, Oregon

14.2 - ATI Annual Technology Fair.
Aug. 10. ATI Industrial Automation,
Orion Township, Mich.

14.3 - Global Automotive Lightweight Materials Detroit Congress.
Aug. 22–24. COBO Center, Detroit, Mich.

14.4 - Westec.
Sept. 12 –14. Los Angeles Convention Center, Los Angeles, Calif.

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