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Although the presence of tensile stresses is obvious in drawing, compression also plays a significant role because the metal is squeezed down as it passes through the die opening. The die angle influences the drawing force and the quality of the drawn product.
Which type of stresses is are involved in the wire drawing operation?
Which of the following stresses is takes place during performing the wire drawing operation? Explanation: Wire drawing is a forming process in which a round metallic bar is pulled by a machine by generating indirect compressive stresses in the bar.
What are the factors control the wire drawing process?
Deformation during wire/rod drawing is influenced by a number of factors which include steel chemistry, approach angle, lubrication, drawing speed, and reduction as the most significant.
How does wire drawing work?
The wire-drawing process consists of pointing the rod, threading the pointed end through a die, and attaching the end to a drawing block. The block, made to revolve by an electric motor, pulls the lubricated rod through the die, reducing it in diameter and increasing its length.
What are the defects in wire drawing parts?
Defects from the deformation process, i.e., center burst or cracking (cupping). This defect will occur for low die angles at low reductions. For a given reduction and die angle, the critical reduction to prevent fracture increases with the friction.
Which of the following types of stresses is applied during the process of rod or tube drawing *?
Which of the following types of stresses is applied during the process of rod or tube drawing? Explanation: Rod or tube drawing is a deformation process in which the metallic material in the form of cylindrical bar is pulled by the help of a converging die. In general, the tensile stress is applied during the process.
Which of the following types of stresses is are involved in the flange of blank in the deep drawing process?
The stress in the flange region during the deep drawing process is a combination of radial tensile drawing stress and a tangential compressive stress (hoop stress). The main defects of deep drawn parts are wrinkling and/or necking.
Why wire drawing is usually a cold working process?
Although similar in process, drawing is different from extrusion, because in drawing the wire is pulled, rather than pushed, through the die. Drawing is usually performed at room temperature, thus classified as a cold working process, but it may be performed at elevated temperatures for large wires to reduce forces.
Why is lubrication difficult in wire drawing?
The wire rod has hard oxide layer or scale on its surface, which must be removed, because otherwise, the abrasive scale will decrease die life as well as damage the surface quality of drawn wire.
Is the major point of concern in the wire drawing operation?
Die design is very important in wire or rod drawing. There are several types of defects in a wire/rod drawing process. Some defects such as scabs (irregularly shaped flattened protrusions) occur due to defective raw material. Some defects occur due to faulty design of die and process.
What are the advantages of wire drawing?
The advantages of wire and rod drawing of other applications are: Good surface finishing. Adaptability to mass production. Close dimensional control. Improved dimensional properties. Economical benefits.
What is wire drawing and bar drawing?
Bar or wire drawing is a deformation process in which the work piece in the form of cylindrical bar or rod is pulled through a converging die. The stress applied is tensile. A bar or rod is drawn down in order to reduce its diameter. In general, drawing results in reduction in area of cross-section.
What is meant by wire drawing and tube drawing?
Types of Drawing Process: Wire Drawing, Rod Drawing and Tube Drawing. Drawing is a metal forming process used to reduce cross section and increase length of work piece. This process associated with tensile force which distinguishes it from other metal forming processes like extrusion, forging etc.
What is the optimum number of dies for wire drawing?
Summary. Wire drawing is one of the processes where optimization techniques have proved able to provide improved solutions in terms of drawing force, but also of strain and stress homogeneity—essential for damage and for residual stresses, two major characteristics of the drawn wire.
Which of the following angle influence the drawing force and the quality of drawn products?
Explanation: Die angle influence the drawing force and the quality of drawn products. Die angle should be kept appropriate for better surface finish.
Which of the following metal forming processes performs squeezing out of material through a hole?
4. Which of the following metal forming processes performs squeezing out of material through a hole? Explanation: Extrusion process is a type of metal forming process, in which the material is forced or squeezed out through a hole called die. This process is very similar to squeezing out the toothpaste from the tube.
Which of the following methods of casting is best suited for casting of hollow pipes and tubes *?
Explanation: Centrifugal casting technique is the best technique and widely used for casting the tubes and hollow pipes which are symmetric in structure with a concentric hole.
Which pattern is used to produce a number of casting?
Explanation: Match plate pattern are usually used for manufacturing small castings on a big scale. Hence, piston rings of the engine are made using this pattern.
Which of the following types of stresses are induced in the stretch forming process?
Stretch forming is a sheet metal forming process in which the sheet metal is intentionally stretched and simultaneously bent to have the shape change. It is a type of cold drawing. Stress-induced is mainly tensile.
Why deep drawing is important?
By using deep-drawing you are guaranteed to have products produced with exceptional detail and accuracy. Deep drawing uses less material in the manufacturing process, therefore it reduces the cost but also waste. Other processes such as turning have a very significant waste material cost.
What is cupping and deep drawing?
Deep drawing (cupping) is a manucfacturing process used to create deep, seamless och round shapes from sheet metal. When deep drawing, a tool (called a plug) punches sheet metal into a die. The sheet metal takes the same shape as the tools, commonly a round shape with a radius and depth.
Who invented wire drawing?
Wire drawing has been around for thousands of years and in fact the first example of metal being formed into wire comes from 5000 years ago in Ancient Egypt where jewellery was created by twisting strips of metal into a hollow tube and then rolling this between two flat surfaces to form a thin, solid wire.
Which lubricant is used in wire drawing?
There are two types of lubrication processes used for the cold drawing of wire: dry soap lubricants and liquid lubricants. Liquid wire drawing lubricants completely immerse the wire in a neat oil, water miscible, or solution synthetic lubricant.
What is drawing lubricant?
Drawing lubricants is an invert emulsion that thickens while water is added. The viscosity changes from thin to thick which makes it an ideal drawing lubricants.
