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FABRICATION WELD DUCTING SOFT SOFT STEEL AND ITS TREATMENTS


Mild steel is a steel alloy that contains a high proportion of carbon as the main alloying agent. Alloys are simply a mixture of one or more metals and non-metals, which have specific, improved properties compared to the base metal. Mild steel is the type of steel used in most internal and external steel applications in the UK.

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Steel mainly consists of iron alloys with 0.2% to 2.1% carbon, which acts as hardening agents. In addition to carbon, there are many metallic elements that are part of steel alloys and have a strong influence on their properties. Elements other than iron and carbon used in steel can be a mixture of all or part of them; Chromium, manganese, tungsten, and vanadium.
In addition to carbon, these elements act as hardeners. By hardeners, we mean that they create dots in the layers of the iron crystal lattice that prevent the layers from sliding on each other. To do this, they attach themselves to the gaps in the crystal structure and block the movement of the network.
This is simply the reason why steel is harder than iron and adds alloying agents. When the alloying agents are varied, different types of steel are produced with different practical industrial uses. The higher the proportion of carbon and other hardening agents in the steel, the harder the steel becomes, but this leads to a reduction in ductility.
Mild steel can also be considered non-stainless steel. Mild steel and low-carbon steels differ from stainless steel mainly in their much lower chromium content. Stainless steels contain a much higher percentage of chromium than standard soft steels, which gives them better resistance to corrosion but involves higher financial costs.
We have listed the main properties of mild steel and its use are as follows:
The addition of carbon does make mild steel stronger and stiffer than other types of steel. This increased hardness is balanced by a reduction in the ductility of this alloy. Carbon atoms fix themselves to the interstitial sites of the iron matrix and increase its strength.
Other than the maximum upper limit of 2 % carbon in the mixture of carbon steel, the percentages of manganese at 1.65%, copper at 0.6% and silicon at 0.6% are fixed. The percentages of the elements; cobalt, chromium, niobium, molybdenum, titanium, nickel, tungsten, vanadium and zirconium can vary from batch to batch.
Mild steel has ferromagnetic properties.  This makes it ideal for manufacture of electrical devices and motors parts.
The average industry grade mild steel density is 7.85 gm/cm3 and its Young’s modulus is 210,000 Mpa (measure of stiffness).
Mild steel is the cheapest and most versatile form of commercially available steel used as sheet metal, bar, rod and sections.
The high amount of carbon within its structure makes mild steel vulnerable to corrosion (rust). If you need a rust free sheet metal steel product then surface finishing/treatments will be needed or stainless steel will need to be substituted for mild steel.
These are the main properties and uses of mild steel. We use mild steel sheets for a variety of sheet metal processing for our customers every day. However, most sheet metal products that we manufacture from mild steel must have protection either as a surface treatment, for example, zinc coating, Zintec or surface treatment. Powder coating against corrosion.
Zintec plate - DC01 + ZE 2.5 / 2.5APC, phosphate and chrome-plated according to EN 10131/10152
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Cold-reduced mild steel sheets are first electrolytically cleaned and then etched to obtain a clean, smooth surface without oxide before they are coated with uniform electrodeposition of zinc or a zinc-nickel alloy. Coating processes are used to control the thickness of the finished coating on the sheet. The coating process can be used to produce single-sided and differential coatings as well as the most commonly supplied double-sided standard coatings.
We use Zintec sheets for metalwork that do not require full treatment of the zinc plate but would rust if they were made of mild steel only. Many internal components are perfect for zintec steel such as electronic chassis, shelves for lighting fixtures, brackets, sheet metal housings and cupboards as well as all sheet metal products that are not wet and are not important from a cosmetic point of view. You can find many examples of zintec sheet metal components on our website. The sheet can always be made from Zintec sheet, even if it then has to be coated with powder since this zinc layer can act as a good protective primer for the component.
Hot-dip galvanized sheet - DX51D Z275 NAC according to EN 10142/10143
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The hot-dipped galvatite sheet consists of an integrated continuous line which anneals and covers both sides of a coil of cold-rolled sheet steel by immersing it in a bath of molten zinc with a thin layer of zinc. The line contains devices that control the mass of the coating, the quality of the surface and the flatness of the metal strip after the zinc coating. We use galvanized sheets similar to zintec sheets, but they have a thicker layer of zinc and therefore offer a little more protection against corrosion.
Galvanization and passivation of mild steel sheets
Galvanization and passivation have traditionally been used to provide protection against "sacrificial" corrosion on mild steel, and are generally deposited in commercially available sheet metal in thicknesses between 5 µm and 25 µm depending on the levels of corrosion protection of components required for finishing. Sheet metal components that require galvanized coatings are generally passivated on the surface by immersion in a chromate solution to increase the resistance of zinc to atmospheric corrosion. Additional surface treatments can be applied after chromating to improve certain properties, for example:
  • Seal the outer surface - to improve corrosion resistance
  • Integral lubricant - to improve the rolling torque properties of fasteners/threads
With the right pretreatments, zinc can be deposited on almost any base metal. However, the most common are iron materials (those that contain iron). However, certain materials such as various cast iron and carbonitrided steels need to be treated in certain types of zinc baths.
Zinc is deposited from one of these three main types of coating solution;
  • Acid chloride
  • Alkaline noncyanide
  • Cyanide
The deposits obtained from each of these solutions have different properties
These include differences in appearance, the successful covering of deep depressions, layer thicknesses and certain mechanical properties such as the ductility of the resulting final deposit.
After galvanizing, the coatings are usually passivated to increase the zinc protection on the steel by dipping the sheet metal parts in chromate solutions. There are a variety of chromate coating classes that, in addition to their different cosmetic appearance, can offer a different level of corrosion protection, although the appearance cannot be guaranteed from batch to batch. With the introduction of the ELV and RoHS guidelines (early 2006); Liabilities containing hexavalent chromium (Cr VI) cannot be applied to components that are intended to be used in the automotive and electrical / electronics industries (with certain exceptions and exceptions). The chromate solutions currently used commercially are:
  • Transparent / Blue - Contains Cr III ELV / RoHS compliant
  • Thick film trivalent - Contains Cr III ELV / RoHS. This passivation class was developed to achieve color corrosion resistance / yellow passivation as an ELV / RoHS-compliant alternative
  • Black passivation - Contains Cr VI not ELV / RoHS compliant
(For more information on their specific uses, we can speak directly to zinc pans for you.
We are usually asked to have components made of mildly galvanized sheet steel and clear, passivated or passivated black, for which protection against atmospheric corrosion is more important than the final cosmetic aspect. Galvanizing as a surface treatment can vary in color from batch to batch and the components involved can be problematic. If a finish or consistent color is required, a powder coating or wet spray can be considered.

Ducting is a channel or media where the production material is distributed or the rest of the production, usually in the form of fine dust from the production machine (dryer, hopper, etc.) to the next production process (chute, conveyor, burner, etc.).

Cleanholes are usually installed at several points for access to cleaning (cleaning), especially in areas such as bending around the elbow, tee and places that are prone to clogging.

The type of plate material used mostly uses carbon steel plates, some companies also use ducting with steinless steel plates. This is because the production material that passes through the ducting contains many chemicals that easily damage the ducting walls made of ordinary carbon steel plate.

How do you fabricate ducting?
The ducting fabrication process seems trivial, but if it is not done properly - especially in the marking, rolling and pinpointing process - the result will be bent like a snake, or it could be an oval shaped duct surface.

Then how to make the correct ducting?

Next I will give an example of 316 L Ducting SS (Steinless Steel) fabrication which is one of the sections of several elongated ducting series, with the following sizes:


- Length = 6100 mm,

- Outside diameter (OD) = 1200 mm,

- Plate thickness = 6 mm,

- Flange = 2 sets (right and left)

- Cleanhole = 2 sections with a size of 400mm x 300mm.

- Mainhole = 1 section with a size of 580mm x 580mm
Ducting Steinless Steel
The manufacturing stages of the sheaths are as follows:
1. Preparation of work materials.

2. Marking and cutting plates.

4. Folding / rolling of the plate

5. Pinch / connect the roller plate.

6. Make and install the flange and clean the hole.

7. Welding / welding.

8. Finishing.

Please click one by one on the above steps for more explanation.

Thus the explanation of the understanding of ducting and ducting fabrication steps. For more details, follow my next post.May be useful.

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