(a)
The force vs. reduction in height curve in open die forging of cylinder for no friction between the flat dies and the specimen.
(a)
Explanation of Solution
Given:
The initial thickness of the specimen is
The initial radius of the specimen is
The friction coefficient is
Formula used:
The expression for the flow stress is given as,
Here,
The expression for the true strain is given as,
Here,
The expression for the final radius by equating the volume is given as,
The expression for the forging force is given as,
Here,
The expression for the average pressure is given as,
The expression for final height for
The expression for final height for
The expression forfinal height for
The expression for final height for
The expression for final height for
Calculation:
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
Reduction (in ) | Forging force (in ) |
The plot between forging force and reduction in height is shown in figure (1) below,
Figure (1)
(b)
The force vs. reduction in height curve in open die forging of cylinder for
(b)
Explanation of Solution
Given:
The initial thickness of the specimen is
The initial radius of the specimen is
The friction coefficient is
Formula used:
The expression for the flow stress is given as,
Here,
The expression for the true strain is given as,
Here,
The expression for the final radius by equating the volume is given as,
The expression for the forging force is given as,
Here,
The expression for the average pressure is given as,
The expression for final height for
The expression for final height for
The expression forfinal height for
The expression for final height for
The expression for final height for
Calculation:
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
The final height can be calculated as,
The final radius can be calculated as,
The true strain can be calculated as,
The flow stress can be calculated as,
Refer to table 2.2 “Typical values of strength coefficient
The average pressure can be calculated as,
The forging force can be calculated as,
For
Reduction (in ) | Forging force (in ) |
The plot between forging force and reduction in height is shown in figure (2) below,
Figure (2)
Want to see more full solutions like this?
Chapter 6 Solutions
EBK MANUFACTURING PROCESSES FOR ENGINEE
- Write a detailed note on "Hydrostatic Extrusion". Also draw diagrams to explain the process of hydrostatic extrusion.arrow_forwardThe process of extrusion is usually described as a semi-continuous operation. Explain it?arrow_forwardExplain what you know about crystallographic anisotropy, which has an important place in sheet metal forming operations, with the help of shapes and formulations.arrow_forward
- In open-die forging, disc of diameter 200 mm and height 60 mm is compressed without any barreling effect. The final diameter of the disc is 400 mm. The true strain isarrow_forwardWhat is K constant in sheet metal bending? How to calculate shear force and extrusions? Formulas?arrow_forwardA cylindrical part is warm upset forged in an open die. The initial diameter is 50 mm and the initial height is 40 mm. The height after forging is 30 mm. The coefficient of friction at the die-work interface is 0.25. The yield strength of the work material is 285 MPa, and its flow curve is defined by a strength coefficient of 600 MPa and a strain-hardening exponent of 0.12. Calculate the strain at yield point.arrow_forward
- A tube of 12 mm external diameter and 1mm thickness is to be reduced to 16 mm external diameter and 0.5 mm thickness. The die angle is 24º and plug angle is 16º. The coefficients of friction at die and tube interface and tube and plug (mandrel) interface is 0.5. The flow stress of tube material is 340 N/mm2 . The tube drawing is carried at a speed of 0.4 m/s. Calculate the fixed plugarrow_forwardAn austenitic stainless steel plate with a width of 100 mm, a length of 150 mm and a thickness of 50 mm is to be hot forged in a hydraulic press so that the width remains constant. If it is to be reduced in one step to a thickness of 40 mm, calculatea) the actual load that needs to be applied at the end of the forging, as well as b) the corresponding deformation energy. In previous plane strain compression tests, it was found that the material exhibits an average plane strain yield stress of 80 MPa at the forging temperature. Assume that the efficiency of the process is 0.6 Answer: Pfr= 2.5 MN ; WTr= 25 kJarrow_forwardA solid cylindrical slug made of 304 stainless steel is 150 mm in diameter and 100 mm high. It is reduced in height by 50% at room temperature by opendie forging with flat dies. Assuming that the coefficient of friction is 0.2 and the flow stress of this material is 1000 MPa, calculate the forging force at the end of the stroke. Manufacturing processesarrow_forward
- A 300mm thick slab is being cold rolled using roll of 600mm diameter.If the coefficient of friction is 0.08. Determine the maximum possible reduction.arrow_forwardA 40 mm thick plate made from 410 grade stainless steel is to be reduced to 34 mm in one pass in a rolling operation. As the thickness is reduced, the plate widens by 3%. The entrance speed of the plate is 13 m/min and the roll radius is 310 mm with a rotational speed of 30 rpm. To do 5.1 If the final width of the sheet is 200 mm, calculate the required roll force. 5.2. Explain what is roll flattening, its effects and how it can be reduced.arrow_forwardA solid cylindrical work piece is reduced in height by an open die forging process using flat dies on a mechanical press, powered by a 20 kW motor which operates at 35 strokes per minute with a stroke length of 160 mm. The work piece is 60 mm high and 100 mm in diameter and is to be reduced in height by 15%. The coefficient of friction during the operation is 0,18. Calculate the flow stress of work piece material if the press is set to operate at 90% of its maximum capacity.arrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY