Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Cylinder Series Test
A series of round bars of various diameters are austenitized and quenched into oil or water. The bars are long sufficient hence the cooling of section at the middle of the length is not affected via the ends. After hardening every bar is cut in half and hardness measured on different points along a diameter. The graph in between distance and hardness from the centre is then prepared as in following figure. From such graph the diameter at that 50% of the structure is martensite is calculated. While such graph the diameter is plotted against bar diameter, this becomes possible to find out the bar diameter whether 50% martensite would form at the centre. This is termed as critical diameter for such quenching medium. Because the rate of cooling is less for oil quench after that for water quench, the critical diameter, of any type of steel will be less for oil quenching than for two water quenching. Quench severity is an index in which quantitatively explains the quenching situation. Such index indicated by H is explains as given ratio.
H = Heat transfer coefficient between steel and fluid/Thermal conductivity of steel
Figure: Variation of Hardness along with Depth in Water-quenched Cylindrical Bars of (a) Plain Carbon Steel, (b) 1% Cr-V Alloy Steel
Obviously, when H → ¥, it shows the severest condition of quench, sense that surface of steel instantly reaches the quenching medium temperature. The critical diameter for that, an unrealizable and ideal situation is termed as ideal critical diameter. For infinite H-value ideal critical diameter and the critical diameter will be similar. For other H values the critical diameter will be slighter. Given figure illustrates the relationship in between ideal diameters and critical diameters for various H-values. Table no.10 illustrates relative values of H such can be acquired in different quench media beneath various condition along with value of one for still water as base.
Figure: Relation between Critical Diameter, Ideal Critical Diameter and Severity of Quench
Table no: Relative Quench Severities
Agitation of Quenching Medium
Movement of
Pieces
Severity of Quench
Air
Oil
Water
Brine
None
0.02
0.3
1.0
2.2
Moderate
-
0.4 - 0.6
1.5 - 3.0
Violent
0.6 - 0.8
3.0 - 6.0
7.5
Violentor spray
1.0 - 1.7
6.0 - 12.0
Dismantle crank case and explode main shaft , counter shaft, gear shifter drum and kick spindle assembly and check sequence of parts fitment while dismantling: Check all gear teeth
(a) What is value of drive chain slackness? (b) Write about cleaning procedure and adjustment of drive chain. (c) What is the wear of drive chain, sprocket and adjustment of
truss problems
is it correct tosay tha the heat content of the system is 5 kv.
Generation of steam at constant pressure: Steam is pure substance. Like any other pure substance it can also be converted into any of the three states, that is, solid, liquid
Q. How can we use Cereals? Foundry cereal is finely ground corn flour or corn starch. It (0.25-2%) increases the green and dry strengths of the moulding sand. Since the cereal
Find out change in diameter: A cylindrical shell, 0.8 m in a diameter and 3 m long is along with 10 mm wall thickness. If the shell is subjected into an internal pressure of 2
Determine minimum value of weigh to cause motion: Determine minimum value of weight W required to cause motion of block, which rests on a horizontal plane. The block weighs 3
Physical significance of damping coefficient and it''s unit.
Derive steady flow energy equation?Also give applications of steady of steady flow energy mathematical equation?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd