FSM Shop Report
FSM Shop Report
FSM Shop Report
By: Bhupender Singh Chugh Shop no. 2 at Pantnagar plant of Ashok Leyland is meant for the fabrication of frame side member (FSM) of the Heavy Load Trucks. Thin sheets ( Cold Rolled) of mild steel are used as raw material. The basic processes carried out in the manufacturing are as follows:
(a) Forming:
Thin sheets of MS are bent into U shape by using roll forming. Sheet is passed through a series of rolls to produce the required shape.
(b) Punching:
In this operation holes of various diameters are punched into the work piece using punching machine (sonam). The whole punching operation is carried out in a sound proof chamber using two CNC punching machines.
2) WATER RINSE
The work piece is fed through a series of nozzles through which water with high velocity is forced on the surface to properly clean the surface.
3) ACTIVATION
Surface Activation activates the metal to obtain fine crystalline structure during phosphate coating which will increase corrosion resistance and adhesion properties. Crystalline structure less than 10 Microns is always preferable. If we are not using activation, the phosphate crystal size may be large and results in voids in Phosphate coating (Gap between structure will be large). Corrosion will take place at the voids.
4) PHOSPHATING
Phosphate coatings are used on steel parts for corrosion resistance, lubricity, or as a foundation for subsequent coatings or painting. It serves as a conversion coating in which a dilute solution of phosphoric acid and phosphate salts is applied via spraying or immersion and chemically reacts with the surface of the part being coated to form a [3] layer of insoluble, crystalline phosphates. Phosphate conversion coatings can also be used on aluminum, zinc, cadmium, silver and tin The performance of the phosphate coating is significantly dependent on the crystal structure as well as the weight. For example, a microcrystalline structure is usually optimal for corrosion resistance or subsequent painting. A coarse grain structure impregnated with oil, however, may be the most desirable for wear resistance. These factors are controlled by selecting the appropriate phosphate solution, using various additives, and controlling bath temperature, concentration, and phosphating time. Phosphate coating used here is of zinc phosphate basically meant for rust proofing.
FRAME PAINTING
Frame painting is done to provide finish and make the surface corrosion resistant. The following processes takes place for painting of a Frame member.
1) POWDER COATING
Paint in the powdered form is given negative charge and is bombarded using an air pressurized (5-6 bar) electrode gun on the frame part having a positive charge. The charging is done to increase the adhesion between the two types of materials. 2) IR OVEN In IR oven Pre baking process is done where the powder coated part is heated to temperatures of about 120 C to wipe off any moisture content present and bring the powdered form to an almost molten state. 3) PC OVEN Then the part is finally baked in a PC baking oven at a temperature of 200 C for around 30-35 minutes 4) PC COOLING The blank is then slowly cooled to room temperature using air cooling by PC cooler.
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QUALITY CHECK
After the FSM is fully manufactured, various tests are performed on it to ensure the recommended quality. dry film thickness test is performed to ensure uniform powder coating on the FSM Test was performed to check for any gloss on the surface