Blog Archives - Welding Alloys Manufacturers In India

Resolve Wear Factors using Effective Hardfacing Electrodes

In any discussion of welding on wear-prone applications, reference is made to the hardness of weld deposits &what hardfacing electrode can be used for different applications. But the word “hardfacing” is actually a misnomer. In reality, what any maintenance engineer in any plant is looking for is an ideal solution to tackle the wear in the particular application. So, in essence, the engineer is looking for a wear-facing product with the necessary properties to tackle the wear. not just hardness.
So, to understand the effective use of hardfacing welding electrodes, we need to understand what is wear &and learn more about the wear factors.
Wear can be described as the process of constant loss of material or material integrity from a solid surface. Wear is a surface phenomenon and generally, causes of wear can be mechanical or chemical. The study of wear and related processes is also known as Tribology.

The factors of wear can be classified into two types –Primary wear factors & Secondary wear factors.

Primary Wear Factors-Abrasion, Friction & Impact

Secondary Wear Factors-Erosion, Corrosion, Heat, Cavitation

The seven factors listed above can all act on any component, causing the wearing out. There are various methods and solutions available to help combat these wear factors. However, let us first look at why we have classified them separately as primary and secondary wear factors.

The reason is really simple. The primary wear factors of Abrasion, Friction &Impact in general in all industry applications cause more loss of material or wear when compared to the secondary factors. Hence it is critically important to suggest solutions to combat the primary wear. Invariably, we find that some secondary wear factors also accelerate the wear. So, when we suggest solutions for any application, we need to study all the wear factors acting on the application and provide a comprehensive solution.
Typical Example: Let’s take the application of boiler nozzle tip in a power plant. Pulverized coal passes through the boiler tips in a power plant wearing down the component with high impact and abrasion. But, the wear is actually accelerated by the secondary wear factors of Heat, corrosion & Erosion as materials are carried by forced air when it is moving inside the boiler. So we need to select an LH Alloycapable of withstanding all these wear factors. Ador Fontech’sLH 743Nis a special constituent alloy that retains its hardness even at 650 degrees Celsius, making it the most suitable solution for this application, capable of dealing with the multiple wear factors.

One of the unique insights gained from studying the tribology of wear is that all applications in the industry will have a combination of wear factors. There is almost no application across the industry where we have only one wear factor. So when we offer a solution we need to understand the combination of wear factors acting on the component to provide a solution that ensures Life Enhancement.
This is the reason why we must understand the term hardfacing. We must know that simple hardness in the application does not assure us of a component’s longer life. We get longer life with a correct LH Alloy which can tackle all the critical wear areas in the industry and offers the correct alloy combination & hardness. Let us see some industry examples to understand the concept of Wear facing using different Hardfacing alloys.
Typical applications you see in cement plant mines, steel plant mines, and in all mining area applications are repairing the hardfacing material of handling buckets in wheel loaders and porcelain machines.

Typically, with the type of ore or material handled – limestone, iron ore, or coal, the normal wear factors in the application would be high abrasion caused by non-metallic particles on metal combined with impact. So it may be assumed that simple high Iron carbide deposits with 60 HRChardness should ensure a good life.

But in reality, we need to look at the application on-site and observe the terrain or conditions under which it is working. It may be working in the slushy and muddy conditions in high monsoon areas. It’s the type of customer who uses a lot of water to keep the environment friendly. Actually, we need a product with erosion and corrosion resistance. This means we need an Alloy that contains Chromium. Such subtle addition of alloying elements gives longer life. Even for this kind of application, Ador Fontech offers a solution with additional Chromium. For e.g., a product like LH 720 gives excellent Life Enhancement in comparison to conventional hardfacing electrodes with wear protection on secondary wear factors of corrosion and erosion
Let us look at a second scenario. Crushers are used in mining to crush raw material. Depending on the type of industry, we have horizontal impact crusher equipment or hammer crushers with discs. These are widely used in this kind of application because the size of the particles and speed of crushing subject these components to very high impact combined with abrasion. To get the best results, it’s important to use a material with the correct microstructure to withstand the wear factors in such an application.

Normal Fe-Cr-C alloy system Special ADFL alloy system for impact application-

The above illustration shows two different carbide microstructures. The bigger carbide microstructure on the left fails as carbides are chipped off with high impact loading. The minutely, or evenly, distributed carbide on the right is best suited for a high impact & abrasion application and gives better life than the normal coarse carbide microstructure. The carbides are very difficult to dislodge because of the close fine carbide structure. At Ador Fontech, we have developed this special Alloy hardfacing electrode for high impact & abrasion application giving it the highest life enhancement with maximum productivity.

We hope the above salient points on tribology of wear and the three examples explain the problems with wear facing welding electrodes. Ador Fontech brings you a complete range of welding electrodes & Alloys to combat all wear factors. The most critical aspect of this range is that the solution comes in either welding electrode form or as open arc wires, to meet your application’s requirements.
Life enhancement of industrial components has formed the cornerstone of the services offered by Ador FontechLimited, over the last 40 years and more. Partner with us to maintain and repair your equipment for tangible savings with minimum downtime and the highest productivity. Benefit the environment by conserving the non-renewable metal resources of the world.

Reclaim, Do Not Replace

Nickel- Of Vital Importance in Cast Iron Welding

The main problem with welding cast iron comes from its high carbon content. During the welding process, this carbon migrates into the weld metal and/or the heat-affected zone adjacent to the weld metal, making it hard & brittle. This is how Cast Iron gets its reputation for post-weld cracking.

Hence the key to welding cast iron lies in eliminating the risks posed by this higher carbon content which reduces its elongation to about 1%.

Cast Iron in Industry:

Cast iron is a ferrous alloy that has more than 2% carbon in it. Though it can contain anywhere from 2% to 6.67%of carbon, but practically it is found to be between 2% to 4%.

Other alloying elements & types of Cast Iron used generally are listed in the table below:

Advantages of Cast Iron

•It has good casting properties.
•It is available in large quantities, hence produced on a mass scale. Tools required for the casting process are relatively cheap and inexpensive, resulting in low cost of products.
•It can be given any complex shape and size without using costly machining operations.
•It has three to five times more compression strength compared to steel.
•It has good machinability (gray cast iron)
•It has excellent anti-vibration (or damping) properties, hence it is used to make machine frames.
•It has resistance to deformation.

Disadvantages of Cast Iron

•It is prone to rust & loss of Strength.
•Its parts are section-sensitive; due to the slow cooling of thick sections.
•Failure of its parts can be sudden and total parts are crack sensitive
•It has high brittleness.

Applications of Cast Iron

Cast iron is used in making the following products
•Pipes, to carry suitable fluids.
•Different machines
•Automotive parts
•Pots, pans and utensils
•Anchors for ships
•Machine bases

 

Importance of Repairing Cast Iron Components:

Cast iron is widely used in diverse industries with its inherent advantages. It is crack sensitive and also has a reputation of being difficult to weld because of its high percentage of carbon and less conductivity. It is also one of the prime examples for Ador Fontech to showcase our product & process expertise. We not only overcome this problem to successfully repair cast iron components but also give them an even better life than the original components.

Why is Nickel Vital to the Repair?

Nickel-based alloys & high Nickel electrodes are basically used in the welding of all weldable cast Iron as its offers excellent solubility of its carbon component and it’s also a more ductile weld metal. Nickel electrodes also help to reduce the pre-heating and HAZ cracking by providing less carbon pick up in the weld area & the heat-affected zones around weld joints. In all cases, care should be taken to minimize heat input to the base metal. Hence Low Heat Input Welding Alloys like LH 119 & LH CastHeal 113F offer the best solution totally eliminating post-weld cracks. They give a safe and sound joint with considerable Life Enhancement to any broken component.


Ador Fontech expertise in Cast Iron Welding :

From the moment we started our operations in the maintenance & repair welding business 4 decades ago, we had introduced novel products for welding cast iron with products like LH 115 & LH 119. These alloys offer special low heat input properties and unparalleled performance in the last 40 years with our unique methodology of cold welding in Cast Iron components with proprietary expertise in hand heat method.

Today, we offer a complete range of Nickel Alloys in welding Electrodes and in wire form, both TIG and MIG, to take care of all the welding needs of our valued customers. We, at Ador Fontech, take pride in saving thousands of components with our Low Heat input-LH Philosophy to ensure savings in inventory and higher productivity through the Life Enhancement of repaired components.

Reclaim, Do Not Replace

Application of LH Welding Alloys in the Cement Industry

Welding is an important component in the core sector industry driving the infrastructure world – Cement. One of the basic fulcrums which drives this process industry is the maintenance and repair of cement Industry components. Cement is basically manufactured from the raw material ore of Limestone hence the process starts at the mines and ends up as a final product in the Cement Plant. So underlying theme in the manufacturing of cement is Wear –primarily abrasive wear caused by hard limestone combined with impact, heat & erosion in the process.

Why do we use LH welding Alloys in cement plants? This is an important question to answer as most of the material we are going to weld or repair undergo thermal fatigue and continuous wear & tear. Hence welding with the lowest possible amperage with minimal effect on the stressed and overworked component is very important also electrodes to suit welding of dissimilar metals. hence this forms the basis for the repair of all cement Industry components.

The modes of repair by welding can be divided into three types.
1. Protective Maintenance of Wearing Components
2. Maintenance & Repair of worn-out components
3. Breakdown Repairs with highly reliable Components

Now let’s see the three types of repair in detail to understand more about welding cement industry components-

• Protective maintenance:
We understood that the manufacturing of cement involves handling hard limestone meaning very high abrasive condition with impact, heat, and erosion. Hence in many cases, the base material of the component needs protection. This can be as simple as wear protective welding in new components like earth moving buckets or rotary airlock valves designed to give long life before they get worn out with tailor-made solutions like Endurafon&Hardox ready-to-use wear plates.

• Maintenance & repair of worn-out components:
True to its name, this process involves the repair of worn-out components with low heat input LH welding alloys to ensure prolonged life or improved life of the worn-out components prone to abrasion and moderate impact. Some of the typical applications can be impactor arm in mines, Sinter cast roll buttoning in VRM roller and RPR pattern welding build-up with a product designed to perfection like LH Tuff-Tech 58 & LH Weartherm 65.

• Breakdown Repair or Maintenance
The cement industry is a process industry, hence certain components fail due to heavy loads, heat, material fatigue. It’s very difficult to have inventory for these components. Hence these components need in –situ repairs of parts with maximum reliability and performance. Some critical examples are kiln tyre or kiln girth gear. We carry out these repairs with our Star products LH Gold 555& LH 521ideal for welding dissimilar metals or known and unknown combination of steels.

It is a matter of pride for Ador Fontech, that our name remains the first one recalled by all our Cement Industry customers when they’re faced with maintenance & repair welding requirements. We offer tailor-made solutions using specially manufactured Low Heat Input (LH) welding Alloys, Wires and ready-to-use wear plates for all the above welding solutions.

Ador Fontech brings 4 decades of experience in managing all types of applications e.g. joining wear-prone areas & cutting solutions required by valued customers from the cement manufacturing industry. One of the key advantages with ADFL is that apart from supplying the product, we can also carry out repairs at our centralized workshop at Life Enhancement Services, Nagpur. This dedicated site takes up the repair of all cement industry components. We also have a dedicated supply and repair team which offers all maintenance and welding repair solutions at the customer’s site.

This is what makes Ador Fontech’sname synonymous with total solutions for any maintenance & repair problem to the complete satisfaction of customers.

Reclaim, Do Not Replace