Joining

The welding process commonly used for fabricating tailor-welded blanks of dissimilar thickness for automotive applications is

In an arc welding process, the voltage and current are 30 V and 200 A, respectively. The cross-sectional area of the joint is 20 mm 2 and the welding speed is 5 mm/s. The heat required to melt the material is 20 J/s. The...

The most suitable electrode material used for joining low alloy steels using Gas Metal Arc Welding (GMAW) process is

Two surfaces P and Q are to be joined together. In which of the given joining operation(s), there is no melting of the two surfaces P and Q for creating the joint?

Two mild steel plates of similar thickness, in butt-joint configuration, are welded by gas tungsten arc welding process using the following welding parameters. $$ \begin{array}{|l|l|} \hline \text { Welding voltage } & 2...

In a direct current arc welding process, the power source has an open circuit voltage of 100 V and short circuit current of 1000 A. Assume a linear relationship between voltage and current. The arc voltage (V) varies wit...

In an arc welding process, welding speed is doubled. Assuming all other process parameters to be constant, the cross sectional area of the weld bead will

The voltage - length characteristic of a direct current arc in an arc welding process is $$V=$$ $$(100+40l),$$ where $$l$$ is the length of the arc in $$mm$$ and $$V$$ is arc voltage in volts. During a welding operation,...

The welding process which uses a blanket of fusible granular flux is

Under optimal conditions of the process the temperatures experienced by a copper work piece in fusion welding, brazing and soldering are such that

In a linear arc welding process, the heat input per unit length is inversely proportional to

Which two of the following joining processes are autogeneous? $$(i)$$ Diffusion welding $$(ii)$$ Electro slag welding $$(iii)$$ Tungsten inert gas welding $$(iv)$$ Friction welding

A $$DC$$ welding power source has a linear voltage-current $$(V$$-$$I)$$ characteristic with open circuit voltage of $$80V$$ and a short circuit current of $$300A.$$ For maximum arc power, the current (in Amperes) should...

During a $$TIG$$ welding process, the arc current and arc voltage were $$50$$ $$A$$ and $$60$$ $$V,$$ respectively, when the welding speed was $$150$$ $$mm/min.$$ In another process, the $$TIG$$ welding is carried out at...

In solid-state welding, the contamination layers between the surfaces to be welded are removed by

For spot welding of two steel sheets (base metal) each of $$3$$ $$mm$$ thickness, welding current of $$10000$$ $$A$$ is applied for $$0.2$$ $$s$$. The heat dissipated to the base metal is $$1000J.$$ Assuming that the hea...

The major difficulty during welding of aluminium is due to its

Within the Heat Affected Zone (HAZ) in a fusion welding process, the work material undergoes

In a $$DC$$ $$arc$$ welding operating, the length characteristic was obtained as $${V_{arc}} = 20 + 5l$$ where the $$arc$$ length $$l$$ was varied between $$5mm$$ and $$7mm.$$ Here $${V_{arc}}$$ denotes the arc voltage i...

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

Two steel bars each of diameter $$10mm$$ are coaxially friction welded end to end at an axial pressure of $$200MPa$$ and rotational speed of $$400rpm$$. The coefficient of friction between the mating faces of the rotatin...

In arc welding of a butt joint, the welding speed is to be selected such that highest cooling rate is achieved. Melting efficiency and heat transfer efficiency are $$0.5$$ and $$0.7$$, respectively. The area of the weld...

Which of the following is a solid state welding process.

A $$DC$$ welding machine with a linear power source characteristic provides open circuit voltage of $$80V$$ and short circuit current of $$800A,$$ during welding with the machine , the measured are current is $$500A$$ co...

Two metallic sheets, each of $$2.0$$ $$mm$$ thickness are welded in lap joint configuration by resistance spot welding at a welding current of $$10$$ $$KA$$ and welding time of $$10$$ milliseconds. A spherical fusion zon...

In arc welding process, the voltage and current are $$25V$$ and $$300A$$ respectively. The arc heat transfer efficiency is $$0.85$$ and welding speed is $$8$$ $$mm/sec$$. The net heat input (in $$J/mm$$) is

Spot welding of two $$1$$ $$mm$$ thick sheets of steel (density $$ = 8000kg/{m^3}$$ ) is carried out successfully by passing a certain amount of current for $$0.1$$ second through the electrodes. The resultant weld nugge...

Two 1 mm thick steel sheets are to be spot welded at a current of $$5000$$ $$A.$$ Assuming effective resistance to be $$200$$ micro-ohms and current flow time of $$0.2$$ second, heat generated during the process will be

The arc - voltage characteristics of a $$DC$$ power source has a linear power source characteristic of $$V=20+40L,$$ where $$V$$ is the arc voltage in volts and $$L$$ is the arc length in $$cm.$$ The static volt-ampere c...

In Oxyacetylene gas welding, temperature at the inner cone of the flame is around

Which of the following arc welding processes does not use consumable electrode

The temperature of a carburizing flame in gas welding is _______ that of a neutral or an oxidizing flame.

resistance spot welding is performed on two plates of $$1.5$$ $$mm$$ thickness with $$6$$ $$mm$$ diameter electrode, using $$15000$$ $$A$$ current for a time duration of $$0.25sec$$. assuming the interface resistance to...

Two plates of the same metal having equal thickness are to be butt welded with electric arc. When the plate thickness changes, welding is achieved by

Two different pairs of sheets of same material are welded by resistance-spot welding. In one pair, the average radius $$(r)$$ of each spherical bridge is $$0.2$$ $$mm$$ and the number of bridges per $$c{m^2}\,\,\left( n...

For butt welding $$40mm$$ thick steel plates, when the expected quantity of such jobs is $$5000$$ per month over a period of $$10$$ years, choose the best suitable welding process out of the following available alternati...

The voltage-arc length characteristics of a $$DC$$ arc is given by $$V=20+4L.$$ Where $$L$$ is in $$mm$$. During a welding operation arc length is expected to vary between $$4$$ and $$6$$ $$mm$$ with the welding current...

The voltage-arc length characteristics of a $$DC$$ arc is given by $$V=20+4L.$$ Where $$L$$ is in $$mm$$. During a welding operation arc length is expected to vary between $$4$$ and $$6$$ $$mm$$ with the welding current...

Welding of $$C40$$ steel plate of $$10mm$$ thickness required a current of $$16$$amps, while it was $$360$$amps when the plate thickness was increased by $$50\% $$. Estimate the welding current for $$8mm$$ thickness of s...

Preheating before welding is done to

The ratio of acetylene to oxygen is approximately ................ for neutral flame used in gas welding

The electrodes used in $$arc$$ welding are coated. This coating is not expected to

In $$DC$$ welding, the straight polarity (electrode negative) results in

For resistance spot welding of $$1.5$$ $$mm$$ thick steel sheets, the current required is of the order

A low carbon steel is to be welded by the manual metal arc welding process using a linear $$V$$-$$I$$ characteristic $$DC$$ power source. The following data is available. $$O.C$$ voltage of the power source $$=62V,$$ $$S...

In an explosive welding process, the ..................... (maximum/minimum) velocity of impact is fixed by the velocity of sound in the ............. (flyer / target) plate material.

For gas welding a particular job using a neutral oxy-acetylene flame the acetylene consumption was $$10$$ ltrs. The oxygen consumption from the cylinder in liters will be

Manual metal arc welding is to be used for welding two plates each measuring $$800 \times 200 \times 19mm.$$ Given that Length of weld $$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,\,$$$$:180mm$$ Length of electrode$$\,\...

At small variations of are length at operating conditions, the manual metal are welding transformer provides nearly

An arc welding $$DC$$ power source has a linear power source characteristic with open circuit voltage $${V_O} = \,\,80$$ volts and short circuit current $${{\rm I}_S} = 1000amps.$$ The voltage-length characteristic of th...