Best Known Welding Methods From Experts Around The Globe

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Welding is a sculptural process of binding and joining metals or thermoplastics by causing fusion. Welding melts the base metal and a filler material is typically added to the joints to form a pool of molten material. This molten metal then cools down to form a joint.

There are different methods for welding and each has its own pros and cons. For example, there are less common methods for welding processes such as friction welding in which the base metal does not melt.

Some mostly used welding methods as revealed by the experts in non-destructive testing are:

  • Oxy-fuel welding – This method is also known as oxyacetylene welding or oxy-welding in short. It uses fuel gas and oxygen to weld and cut metals.

  • Shielded metal arc welding – Better known as ‘stick’ or ‘electric’ welding, this method uses a flux coated electrode. The electrode holder holds the electrode as it slowly melts away.

  • Gas tungsten arc welding – Also known as TIG, this one uses a non-consumable tungsten electrode to produce the weld. The welded area is protected from atmospheric contamination by an inert shielding gas such as argon or helium.

  • Gas metal arc welding – Mostly termed as MIG, it uses a wire feeding gun that feeds wire at an adjustable speed and flows an argon-based shielding gas or a mix of argon and carbon dioxide over the weld puddle to protect it from atmospheric contamination.

  • Flux-cored arc welding – Almost same as MIG except the fact that it uses a special tubular wire filled with flux. It can be used with or without shielding gas, depending on the filler.

  • Submerged arc welding – This method uses an automatically fed consumable electrode and a blanket of granular fusible flux. The molten weld and the arc zone are protected from atmospheric contamination by being “submerged” under the flux blanket.

  • Electroslag welding – This one is a highly productive method using single pass welding process for thicker materials between 1 inch and 12 inches in a close to vertical position.

There are a number of companies providing services for welding inspection, welding supervision and non-destructive testing (NDT). Inspection is readily necessary after the job is done and should not be left out, since it might prove to be dangerous afterwards.

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How Important Is The Job of A Welding Inspector?

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Welding examination isn’t something that can be considered lightly. There can be lives relying upon the precision of the investigation. Defective welds that lead to the death or property loss make it to the news all the time. These defects now and then are blamed on specialists of welding inspection. In the event that the assessor had done his activity legitimately, the destructive occasion could have been dodged. This claim sometimes is legitimate; assessors commit errors simply like some other individual in the creation chain. Be that as it may, a reviewer can’t examine quality into the item. The nature of a weldment must be set up at the earliest point of the venture & finished to the end. In the event that any progression in the activity isn’t built up and completed with quality as the most important requirement, the likelihood of defect exists.

In years past, poor welds caused numerous more disastrous disappointments than happen today. Boilers detonated, ships sank, structures and extensions crumbled, and pipelines exploded as often as possible. These calamities wound up far less successive as codes and norms were built up.

One of the principal things an examiner must know is which code or standard ought to be utilized for the examination criteria—both the code of development and the code to qualify the welding methods and welders. These necessities must be sketched out in job specifications. The overseer ought not make presumptions or depend on his judgment for setting the standard. In the event that it isn’t mentioned in the determinations or on the illustrations, the overseer ought not continue without proper clarification.

Prior to any welding, an inspector must confirm that the welding methodology are in consistence with the material standard or code. At times, a client builds up a standard that isn’t referenced to a specific code. This is frequently the case with vast organisations. In these cases, the client standard wins.

The welding assessor must check that the welders are qualified and confirmed to the correct code or standard. Welder capability is built up by testing. A welder who effectively plays out a test and gets an accreditation report is called a confirmed welder. The inspector may need a welder to play out an exhibition for a sensible reason, for example, numerous defects & poor workmanship.

Material traceability stands as an outright need for all tasks. On the off chance that a defect happens and responsibility is included, verification of material quality can explain the reason for it. The examiner can just prescribe certain extra tests to guarantee that the material is of adequate quality for utilization.

Defining Forensic Engineering And Failure Analysis

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Failure analysis on a metal is performed by systematic examining, analyzing and testing the failure or flaw, gathering information about the application, component and history, which is further followed by a detailed visual examination. Failure analysis is a part of nondestructive testing which is scientifically known as magnetic particle testing, dye penetrant testing, low magnification, etc. High magnification examination and destructive testing is also sometimes applied like, sectioning the sample for Metallographic micro analysis, Chemical Analysis, Hardness testing, Mechanical testing.

These tests can only performed by a certified welding inspection team in Melbourne.

Macro Examination

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Macroetching is the procedure of etching a sample and evaluating it macro structurally at low magnifications. It is a very frequent technique used for evaluating steel products. There are many different procedures for rating a steel sample by graded series of photographs. The images shows the incidence of certain conditions and is applicable to carbon and low alloy steels.

A number of different etching reagents may also be used depending on the type and process of examination to be applied. You should know that steels react differently to etching reagents because of variations and difference in chemical composition, heat treatment, method of manufacturing and many other factors.

Macro examinations are also performed on a polished and etched cross-section of a welded material. During the testing process, a number of features can be determined including the sequence of weld, weld procedure and qualifications tests. Any defect on the sample can be assessed for compliance with relevant specifications. It can be a slag, lack of weld penetration, porosity, lack of sidewall fusion and poor profile of a weld.

Micro Examination

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Micro examination is performed on specimen either cut to size or mounted in a resin mold. At first they are polished to a fine finish and then etched in an appropriate chemical solution prior to examination on a metallurgical microscope. Micro examination is performed to assess the structure of the material. It is also very common to examine for metallurgical anomalies such as third phase precipitates, excessive grain growth, and various other reasoMicro Examinationns. Many routine tests such as phase counting or grain size determinations are performed in conjunction with micro-examinations.

Forensic engineering and failure analysis of a metal are all high profile examinations, which are conducted to find out even the simplest flaw in a material component.

Hiring A Welding Inspector – Smart Business Practice

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Welding inspections and supervision are among the most important requirements of any manufacturing business to ensure a high quality product that promotes efficiency and safety. Hiring a welding supervisor in Melbourne is an act of high ROI for the company.

What is the requirement of inspection?
Inspection of welds is significant for a number of reasons, the most basic one being to determine whether its current state is considerable enough for its proposed application. It is a necessity to have a list of measurements for enhancing the quality of the weld. Valuation of the weld characteristics includes the size of it and the current existence of cessation. The size of the weld is very important as it correlates with its strength and performance. Undersized welding machines may not hold off stresses that are applied during a service. On the contrary, oversized machines can cause overstress, which will lead to distortion of the welded component.

Why hire a welding supervisor?
When the frustration of dealing with the loss is compared with the time spent in dealing with the issue, it has 1468669114.jpgbeen seen that the latter has won in most of the cases. However, this (spent) time can be avoided by hiring a welding supervisor who puts in their effort to make sure a business produces quality goods and runs on profit. One can stay calm knowing that they have
the service of trained and experienced specialists at their disposal. In addition, a welding supervisor ensures efficacy of all the fine details that are reviewed during an inspection performed by the professional. It means nothing is overlooked that might jeopardize the quality of the products later.

At the end of the inspection, a final report is provided mentioning the following:

The confirmation of the welding level to comply with the relevant standards

The dimensional checks for future references

The confirmation of all specifications and requirements have been met

The review of the Operator’s Manual

Getting deeper into the inspection
Welding inspections not only ensure the welder for quality craftsmanship, but also let him understand the procedure and concern of the work. Special training and a mock test may be held if required. The inspection includes testing of filler materials, fluxes, O2 analysis and inert gas composition. The experts determine the welding technique, progression, bead overlap, etc. The inspector himself is an experienced welder who has earned a certification. He is not only limited to welding machines but also conducts all types of inspections like coating inspection, AICIP pressure vessel inspection, radiography, ultrasonic testing, etc.

This shows that a welding inspector is a form of a highly qualified doctor to an overall commercial welding mechanism who treats them to be the best.

Why Should Pressure Vessels Be Inspected & Maintained Regularly?

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Routine maintenance as well as inspection are vital requirements of engineering, and no alternative can be a worthy substitute to them. Even equipment pieces which are tagged as maintenance-free are prone to damage because of general wear and tear. In order for expensive and high-utility gear to provide continued service, effective and regular inspection combined with proper upkeep is a must.

Nowadays, a majority of equipment used in different fields of engineering are defined by extremely toxic attributes. And in this context, pressure vessels deserve a special mention. To begin with, these units are filled with pressurised gases and toxic chemicals. The force inside them is so powerful that it alters the state of the fluids to a certain extent. For instance, gases turn into liquids first, and again get transformed into gases upon being placed in a cycle of condensation. In other words, it works in almost the same way as a freezing mechanism, but like one scaled for handling a stream of liquid nitrogen that has been processed cryonically.

In case a mishap was to occur, especially one involving deterioration or leaking of the pressurised vessels, that caused the contents of the units to escape, it would inflict great damage by allowing flammable substances to form dangerous clouds of toxic fumes. Fortunately, this kind of leak-out accidents are entirely avoidable – through a well-planned inspection and assessment strategy.

According to the mandatory guidelines of AS/NZS 3788, a typical AICIP pressure vessel inspection analyses a unit within an installation so as to check its operational viability. To put it simply, spotting a worn out seal or a damaged fastener, and then recording it for someone else to resolve, is not enough. There has to be a properly structured maintenance plan for impeding safety issues through replacement of potential weak points on time. Whatever the problem is, general wear and tear or inconspicuous, replacing or resolving it punctually is quintessential.

So if your engineering premises make use of pressure vessels, make sure you have the gears checked on a regular basis by licensed and certified inspectors. There are many organisations in Melbourne who offer welding inspection as well as non destructive testing services. All you need to do is choose a reliable and experienced business from among them and allow the pros to handle the maintenance duties of your pressure vessels.

What Do You Understand By Coating?

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In the realm of welding and corrosion, coating can be defined as the sparse layers of any covering substance applied or deposited on the surface of an object, primarily for enhancing its properties. It also helps in forming a protective barrier to prevent the surface from deteriorating because of reaction with the external environment.

The surface onto which any coating is added, is known as a substrate. And the layers of protection keep it from undergoing electrochemical reactions with elements in the open atmosphere. As such, coating aids in ensuring good quality as well as increasing the lifespan of pipelines, structures and other important equipment. It even removes some critical and life threatening flaws, thereby saving millions in terms of financial resources pertinent to premature replacements and repairs.

According to experts offering the service of coating inspection in Melbourne, corrosion coating is usually:

  • A thin layer of some metal
  • Inorganic lining such as that of porcelain and glass
  • Organic coating like paint, varnish, polymeric materials, etc
  • Printed or etched covering or optical film layer

A typical coating might be applied for providing:

  • Resistance against scratches and abrasions
  • Protection from extremely high temperatures as well as fires
  • Wettability and capacity to seal
  • Insulation against the flow of static electric charge
  • Enhanced aesthetics and physical appearance
  • Resistance against corrosion
  • Non-stick or release property
  • Safety from cavitation, erosion, pitting and general wear & tear

Let’s take a look at some fine instances of coating in order to comprehend it better:

  • Components of jet engine covered with cermet
  • Fabrics provided with waterproof lining
  • Components having extrusion coating
  • Layers of anti corrosion and anti rust paint
  • Adhesive tapes
  • Varnish and polymeric material applied on pipelines & structures

There are a wide range of materials out there which act as substrates for coating. The most common ones include steel, various non-metals as well as other metals, paper, wood, plastics and fabric. In the modern times, coatings serve a primary purpose of offering protection to structures & pipes that are either buried deep into the ground or immersed under the surface of water, such as oil platforms & rigs.

In Melbourne, coating inspection is generally carried out by qualified coating inspectors in order to ensure the standard quality necessary for compliance with environmental, safety, operational and economic issues. The inspections are carried out with strong emphasis on industry standards, training and practices. Comprehensive downtime for re-coating and repairs are extensively minimised during these procedures.

Importance of Certified Weld Inspectors

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In Melbourne, as well as elsewhere in Australia, examination & qualification of welding inspection personnel is regulated by the Welding Technology Institute of Australia (WTIA). When a weld inspector becomes certified, it implies that he or she possesses a wealth of knowledge on various aspects, including:

  • Welding codes as well as contract requisites
  • Metallurgy, that is, corrosion resistance, ductility, strength, fatigue life, etc.
  • Fundamentals of cutting, welding and joining processes & equipment
  • Weld defects, reasons and remedies
  • Procedure as well as performance qualification testing
  • Test documentation such as WPQs, PQRs, etc.
  • Fundamentals of NDT (non destructive testing) methods like ultrasonic testing, radiography, dye penetrant testing, eddy current, magnetic particle, and so on
  • Pertinent drawings and symbols

Besides that, a certified individual also has the obvious ability of performing visual inspection.

If you are a newbie in the manufacturing industry and wondering why you need to hire a certified welding inspector, bear in mind that such a professional generally has a lot of experience in addition to weld-related knowledge. He or she can ensure that every phase of any project is conducted as per applicable specifications and codes.

Welding has a wide range of variables that consist of – arc current & voltage, travel speed, polarity, wire feed speed, joint geometry, base metal chemistry, position, filler metal chemistry, tensile strength, fracture toughness, hardness, ductility – and a neverending list. With the presence of all these interdependent variables, having a scientific quality control for welding is absolutely vital. And that is where the certified inspectors come in. A program proceeded with under the guidance of a licensed expert would ensure code compliance and systemic regulation of variables. Moreover, it is a very prudent business move to control the quality of manufacturing processes.

Throughout Australia, a number of high-profile industries, including those of the Aerospace, Oil & Gas, Defense, Energy, Transportation and Construction, necessitate certified inspectors. This is because stakes are generally high in such industries and aftermath of even a single failure can spell catastrophe. Presence of a certified welding inspector on site not only ensures compliance with code requirements, but also prevent weld failures.

Prior to the commencement of production welding processes, it is absolutely imperative to engage a certified welding inspector in advance. The professional would be entrusted with a number of responsibilities, including testing activities, setup before production, and so on. These kind of activities usually take some weeks for completing, and should be reviewed & approved before initiation of client’s production procedures.