haroonkhan – Page 308

Types of Rolling Mills

Dec 13, 2022

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in Mechanical Working Of Metals, Sheet Metal Work, And Powder Metallurgy

The different types of rolling mills are shown in Figure 21.2. In two high rolls mill (pullover), the stock is returned to the entrance for further reduction. In two-high mill (reversing), the work can be passed back and forth through the rolls by reversing their direction of rotation. In three high rolls mill, upper and lower…

Terminology

Dec 13, 2022

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haroonkhan

in Mechanical Working Of Metals, Sheet Metal Work, And Powder Metallurgy

Advantages of Mechanical Working Process Over Other Manufacturing Processes

Dec 13, 2022

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haroonkhan

in Mechanical Working Of Metals, Sheet Metal Work, And Powder Metallurgy

Recrystallization Temperature According to ASME (American Society of Mechanical Engineers), the recrystallization temperature is defined as ‘the approximate minimum temperature at which the complete recrystallization of cold worked metal occurs within a specified period of time.’ Recrystallization reduces the strength and increases the ductility of the metal. Factors which Affect the Recrystallization Temperature

INTRODUCTION OF MECHANICAL WORKING PROCESS

Dec 13, 2022

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haroonkhan

in Mechanical Working Of Metals, Sheet Metal Work, And Powder Metallurgy

Mechanical working is a process of shaping of metals by plastic deformation. When a metal is subjected to external force beyond yield strength but less than fracture strength of the metal, metal is deformed by slip or twin formation. There are two types of mechanical working process: cold working and hot working. When metal is…

WELDING DEFECTS

Dec 13, 2022

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haroonkhan

in Casting And Welding

A number of defects can occur during the welding processes, some of them are shown in Figure 20.51. There are many other defects which are discussed in the following paragraphs. Figure 20.51 Welding Defects Cracks: Cracks occur in the welded joint due to improper welding and solidification of different metals. Cracks may be of the following types. There…

Braze Welding

Dec 13, 2022

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haroonkhan

in Casting And Welding

In braze welding, the molten filler metal is not distributed at joint by capillary action as it happens in brazing or soldering but it is deposited at the point where the weld is required to be made as in the case of gas welding.

Brazing

Dec 13, 2022

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haroonkhan

in Casting And Welding

Brazing is a hard soldering process, but in this process, metal pieces are heated which are to be joined in this place of the bit as in soldering. In a brazing, spelter is used. It is a mixture of copper, zinc, and tin. It is stronger in comparison to soldering joint.

Soldering

Dec 13, 2022

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by

haroonkhan

in Casting And Welding

Soldering is a process of joining two metals by applying low melting point metal or alloy in the gap between the joining parts. The metal or alloy used for filling or joining is known as solder. The melting point of solder is less than 450°C. Solders are divided into two categories. Flux Used: Chlorides fluxes (zinc…

WELDING ALLIED PROCESSES

Dec 13, 2022

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haroonkhan

in Casting And Welding

Thermit Welding

Dec 13, 2022

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by

haroonkhan

in Casting And Welding

Thermit welding is similar to casting. A mixture of powered aluminium and iron oxide is placed inside a vessel. The mixture is ignited by heating to about 1,550°C with the help of barium oxide powder. A chemical reaction takes place in a vessel as shown in Figure 20.50. Figure 20.50 Thermit Welding Due to the chemical action,…

Author: haroonkhan