Welding Metallurgy

Stainless steel is welded using

The nature of submerged arc welding flux with basicity index of 0.5 is

Lap joints are preferred over butt joints in soldering/brazing because

For a good quality brazing, the molten filler alloy should have

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r] . Assertion: In a pure metal weld, elastic modulus in the heat affected zone (HAZ) is the same as that in the base metal. Reason: Coarse grained microstructure in the HAZ results in lower hardness.

Preheating of steel plate during welding is required to

Which of the following is not a solid state welding process?

Which one of the following welding processes uses a non-consumable electrode?

A weldment consists of

Preheating prior to welding is done for the purpose of

In brazing process, the liquid metal fills the gap by which one of the following means?

Match the following: Process Characteristics P. Ultarasonic welding 1. Most commonly used process Q. Plasma arc welding 2. Use of explosives R. Thermit welding 3. Highest temperature S. Shielded metal arc welding 4. Solid state process 5. Use of chemical energy

Which of the following is not a solid state metal joining technique?

Match the following: Group 1 Group 2 P. Thermit welding 1. Globular metal transfer Q. Arc welding 2. Mechanical energy converted to heat energy R. Welding in solid state 3. Exothermic process S. Friction welding 4. Diffusion bonding

Which one of the following carbon equivalent in steel is considered good for weldability?

Match the welding processes in Group 1 with the principal mechanism in Group 2 . Group 1 Group 2 P. Seam welding 1. Ionisation and plasma Q. Explosive welding 2. Exothermic reaction R. Gas welding 3. Interfacial deformation S. TIG welding 4. Interfacial resistance heating 5. Interfacial diffusion of atoms

Brazing fillermetal used for joining steel plates

Melting rate of electrodes in manual metal arc welding (MMAW) process is mainly governed by the

Thermit welding uses the following energy sources.

The grain size in the heat affected zone (HAZ) of a weld is maximum

Flux in welding process acts as

In multipass are welds shot peening is done after each pass to

The titanium alloys are welded using the following process.

Arc welding is done using current, voltage and welding speed of 200 A, 20 V and 0.01 m/s, respectively. The heat input in KJ per unit length is

The order of decreasing weldability among the following steel is P. Fe-0.6% C Q. Fe 0.4% C R. HSLA

For better resistance welding, the metal must have P. high electrical resistivity and low melting point Q. high thermal conductivity R. high electrical resistivity and high melting point S. low thermal conductivity

Two sheets of iron and copper of equal thickness are welded together into one sheet. Iron is in contact with water at 298 K and copper is in contact with steam at 373 K. At steady state, the temperature profile within the sheet will be

Match the joining processes in Group 1 with the filler material in Group 2 . Group 1 Group 2 P. Soldering 1. Silver-titanium alloy Q. Welding 2. Silver-tin alloy R. Brazing 3. Mild steel 4. Lead fluoride

Determine the correctness or otherwise of the following Assertion (a) and Reason (r) . Assertion (a): During welding of aluminium alloys by the gas tungsten arc welding process, direct current reverse polarity (DCRP) mode is used. Reason (r): DCRP facilitate breaking up of the oxide film on the workpiece surface.

"Cold cracking" in the heat affected zone of a high strength steel weld can take place because of

Steels with high carbon equivalent have poor weldability because in these steels during welding

Which of the following is not a fusion welding process?

Of the following welding processes [P] Laser Beam Welding [Q] Submerged Arc Welding [R] Metal Inert Gas Welding the width of the heat-affected zone in decreasing order is

In TIG welding thoriated tungsten electrodes are used because it

In the consumable electrode shielded metal arc welding process, which of the following observations are correct? P. The, weld composition does not depend upon the basicity of the slag. Q. Basic flux is used to achieve low hydrogen content-and low inclusion content in the weld metal. R. Reverse polarity of the direct current power source is used to weld thin sheets. S. Coated electrodes are classified by tensile strength of the weld metal deposit.

In an arc welding experiment, the current, voltage and electrode travel speed were 140 A, 22 V, and 15 cm/min respectively. The heat input per unit length of the weld is given by . . . . . . . . kJ/cm.

Match the welding process in Group 1 with the source of heat in Group 2 . Group 1 Group 2 P. Ultrasonic welding 1. Thermochemical Q. Spot welding 2. Electrical resistance R. SMAW 3. Friction S. Thermit welding 4. Electric arc