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What is the detailed procedure of hot dip galvanizing and electro galvanizing and acid compounds used in it?
Wiki User
∙ 14y ago
GALVANISING
For use in construction at coastal areas it shall be required for galvanizing the
Cross arms and Pole top brackets as following :
All galvanizing shall be carried out by the hot dip process, in accordance with
Specification IS 2629. However, high tensile steel nuts, bolts and spring washer
shall be electro galvanized to Service Condition 4. The zinc coating shall be
smooth, continuous and uniform. It shall be free from acid spot and shall not
scale, blister or be removable by handling or packing. There shall be no impurities
in the zinc or additives to the galvanic bath which could have a detrimental effect
on the durability of the zinc coating.
Before picking, all welding, drilling, cutting, grinding and other finishing
operations must be completed and all grease, paints, varnish, oil, welding slag and
other foreign matter completely removed. All protuberances which would affect
the life of galvanizing shall also be removed.
The weight of zinc deposited shall be in accordance with that stated in
Standard IS 2629 and shall not less than 0.61kg/m² with a minimum
thickness of 86 microns for items of thickness more than 5mm, 0.46kg/m² (64
microns) for items of thickness between 2mm and 5mm and 0.33kg/m² (47
microns) for items less than 2mm thick.
Parts shall not be galvanized if their shapes are such that the pickling solutions
cannot be removed with certainty or if galvanizing would be unsatisfactory or if
their mechanical strength would be reduced. Surfaces in contact with oil shall not
be galvanized unless they are subsequently coated with an oil resistant varnish or
paint.
In the event of damage to the galvanizing the method used for repair shall be
subject to the approval of the Project Manager or that of his representative.
Repair of galvanizing on site will generally not be permitted.
The threads of all galvanized bolts and screwed rods shall be cleared of spelter by
spinning or brushing. A die shall not be used for cleaning the threads unless
specifically approved by the Project Manager. All nuts shall be galvanized. The
threads of nuts shall be cleaned with a tap and the threads oiled.
Partial immersion of the work shall not be permitted and the galvanizing tank
must therefore be sufficiently large to permit galvanizing to be carried out by one
immersion.
After galvanizing no drilling or welding shall be performed on the galvanized
parts of the equipment excepting that nuts may be threaded after galvanizing. To
avoid the formation of white rust galvanized materials shall be stacked during
transport and stored in such a manner as to permit adequate ventilation. Sodium
dichromate treatment shall be provided to avoid formation of white rust after hot
dip galvanization.
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∙ 14y ago
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Is hot dip galvanizing better than electro galvanizing?
It depends on what the metal is going to be used for. A hot dip galvanized steel generally has a thicker zinc layer than an electrogalvanized steel which improves its properties against corrosion. On the other side, the thicker layer might make it inferior in an application in which space is limited.
What are the properties of organic compounds determined by?
The properties of organic compounds is determined by the shape of molecule and the positive and negative charges existing on the molecule. The factor of varying electro-negativity is also very important in determining the properties.
What methods might use to prevent rusting of iron?
The most common way, Electroplating, whether that be Zinc, Nickel or Chromium. Or by using a non-electro immersion process such as EN (electroless nickel), Zinc Phosphate or Manganese Phosphate. Note: Galvanizing (Hot-dipping in molten Zinc) and Electroplating are two totally different things.
The uses of electro magnetic waves in medicine?
The uses of electro magnetic waves in medicine?
Is electro plating a physical or chemical change?
Galvanizing is a physical change. This is because the zinc is coated on the Iron using the magnetic properties of the elements. In the chemical changes a new substance is formed, here the zinc only forms a layer on the Iron,
What is the process of electro galvanizing?
Electro galvanizing is the process of applying a protective metallic coating to an underlying piece of metal.
Is hot dip galvanizing better than electro galvanizing?
It depends on what the metal is going to be used for. A hot dip galvanized steel generally has a thicker zinc layer than an electrogalvanized steel which improves its properties against corrosion. On the other side, the thicker layer might make it inferior in an application in which space is limited.
What is the process that steel goes through to be galvanized?
This answers is for coiled steel strips. Steel strips, after rolling in coil form, are sent to a "Galvanizing Line". The most common and economically viable is "Continuous Hot Dip Galvanizing Line". The steel, after rolling is "Annealed" at required temperature to relieve stresses developed after rolling. After annealing the strip is passed through a "Galvanizing Pot" containing molten zinc. The thickness of coating generally varies from 30 - 300 gm/cm2. The coating thickness is controlled by "Air knives" using air or nitrogen blowers. The coated strip is then "Passivated" using either Chromating liquid or Non-toxic passsivating compounds. For good surface quality, the strip is often skin passed in a rolling mill stand and then tension levelled in a levelling unit after zinc coating. Another process, which is superior to this process is Electro-Galvanizing using an electrolytic process.
What brain imaging method uses radio waves and magnetic fields to produce a detailed image?
Electro-Magnetic imaging
Can you have your gums cauterized in order to lengthen tooth appearance?
Yes, it is known in the dental field as crown lengthening procedure or electro-surgery. This procedure can be completed by utilizing either a scalpel, a laser or a electro-surgical unit. (*Even though the machines are similar The term cauterizing refers to stopping blood and shouldn't be referred to in this case.*)
What are the properties of organic compounds determined by?
The properties of organic compounds is determined by the shape of molecule and the positive and negative charges existing on the molecule. The factor of varying electro-negativity is also very important in determining the properties.
How are the melting points of ionic compounds different from molecular compounds?
Very much higher.
Why is it a good idea to put an iron core in the magnet?
You are probably talking about an electro magnet. For detailed explanations and some good drawings see the link on electromagnets here:
What splits starlight into a spectrum of different colors?
The electro magnetic spectrum - A prism can split light into a spectrum of colors, and starlight is light. Detail your question and you will have a detailed answer, if this answer does not do the job
How is platinum found?
Platinum is a very rare element and expensive to refine. Very small amounts of platinum compounds are found during the processing of copper and nickel ores. The platinum compounds are separated from the other elements in the ore by a variety of electro-chemical processes.
How would you describe the polysomnography procedure?
An overnight stay in a sleep laboratory; while the patient sleeps they are observed and monitored by electroencephalography, electro-oculography, thermistors, pulse oximetry, electrocardiogram.
What does a chemical formula have to do with elements and atoms?
The chemical formula of a compound shows the number of atoms of each element in the smallest unit of the compound. The smallest unit is a molecule for covalently bonded compounds and the minimum number of each of the right kinds of atoms to achieve electro-neutrality for ionically bonded compounds.
