Guide
A Wide solidification range and speedy increase charge throughout solidification will encourage:
(a) planar growth.
(b) equilibrium conditions.
(c) no constitutional supercooling.
(d) dendritic growth.
(e) eutectic formation. - ANS-(d)
Can strain getting old in low carbon steels take vicinity at room temperature? - ANS-Yes
Centerline hot cracking im more likely with:
(a) shallow, spherical welds.
(b) brief weld swimming pools.
(c) huge groove angles.
(d) deep, slender welds.
(e) vertical welds. - ANS-(d)
Compared with pure tungsten, a thoriated tungsten electrode is expected to:
(a) get warmer more speedy.
(b) absorb extra electrons.
(c) have a shorten existence.
(d) operate at a decrease temperature for the equal modern-day.
(e) emit greater ions. - ANS-(d)
Electricity can be performed by using:
(a) atoms and electrons.
(b) electrons and ions.
(c) handiest ions. - ANS-(b)
From Figure eleven.10(Module 20-2014, page 54), estimate the cooling rate for a submerged
arc bead on a 19 mm plate (no preheat) with an power enter of one.Seventy seven kJ/in. -
ANS-sixteen°C/s at 540°C
Hot Cracking for the duration of welding is more likely in:
(a) natural metals.
(b) alloys with a wide solidification range.
(c) alloys with a totally excessive alloy content. - ANS-(b)
, How can porosity because of nitrogen be controlled in welding nickel? - ANS-By using filler steel
containing titanium.
How does yield electricity range with grain length? - ANS-Inversely as the square root of the
grain length.
How many stages are there in a eutectic- one or two? - ANS-Two
If centerline solidification cracking is occuring in welding a structural metallic what's a possible
cause?
(a) electric extension too lengthy
(b) arc voltage too excessive
(c) welding present day and velocity too excessive
(d) weld too large - ANS-(c)
If FCC iron has a denser shape than BCC iron, why does it have a better solubility for carbon? -
ANS-The preferred web site for carbon in BCC iron is smaller than that in FCC iron.
If metals have entire mutual solid solubility what number of phases are fashioned within the
solid- one or ? - ANS-One
In an electroslag flux the contemporary is carried mainly through:
(a) neutral oxides.
(b) holes.
(c) cellular ions.
(d) thermionic electrons.
(e) free electrons. - ANS-(c)
Increasing the preliminary plate temperature (preheat):
(a) has no impact on the cooling rate.
(b) reduces the weld warmness input.
(c) reduces the cooling fee.
(d) causes narrower isotherms.
(e) improves the arc efficiency. - ANS-(c)
Multiplication and subsequent congestion of shifting dislocations causes:
(a) elastic extension.
(b) work or pressure hardening.
(c) a drop in the yield strain. - ANS-(b)
Nickel and copper have complete solid solubility. Copper has a lower melting factor then nickel.
If a 50/50 Cu-Ni alloy is cooled from the liquid what will be the composition of the first solid to
shape?
(a) 50% Cu