Which of the following statement is true about brittle fracture?
In flame hardening, oxy-acetylene flame is used.
An aluminium alloy withsilicon is used for making engine pistons by die casting technique.
Malleable cast iron is produced
The heat treatment process used for softening hardened steel is
A small percentage of boron is added to steel in order to
The aluminium alloy made by melting aluminium with 2 tomagnesium and 1.copper is called
An alloy of copper, tin and zinc is known as
The hardness and tensile strength in austenitic stainless steel can be increased by
The lower critical temperature
White cast iron has a high tensile strength and a low compressive strength.
Pearlite consists of
The steel produced by bessemer or open hearth process is __________ to that produced by L-D process.
Which of the following metal shrinks most from molten state to solid state?
Y-alloy contains
The coordination number of a face centred cubic space lattice is
Which of the following iron exist betweenC andC?
Shock resistance of steel is increased by adding
Which of the following material has nearly zero coefficient of expansion?
The blade of a power saw is made of
When a low carbon steel is heated upto upper critical temperature
Grey cast iron has
Which of the following statements are true for annealing of steels?
Which of the following is an amorphous material?
The machinability of steel is improved by adding
Smelting is the process of
The dieing down of a white flame during the operation of a bessemer converter indicates that the air is burning out silicon and manganese.
Which of the following process of steel making is in operation at Tata Iron and Steel Works, Jamshedpur?
Incoloy, Hastelloy and Vitallium are __________ temperature alloys.
Quenching is not necessary when hardening is done by
Crystal structure of a material is, generally, examined by
A steel containing ferrite and pearlite is
The steel scrap added in the charge of cupola controls the grade of cast iron produced.
Spheroidal grey cast iron has graphite flakes.
Bronze is an alloy of
The material in which the atoms are arranged chaotically, is called
In low carbon steels, __________ raises the yield point and improves the resistance to atmospheric corrosion.
In normalising process, the hypo-eutectiod steel is heated fromC toC above the upper critical temperature and then cooled in still air.
The alloying element which can replace tungsten in high speed steels is
In induction hardening __________ is high.
The steel widely used for motor car crankshafts is
Induction hardening is basically a
The ability of a material to undergo large permanent deformation with the application of a tensile force, is called ductility.
The carbon in the pig iron varies from
The percentage of carbon in cast iron varies from
The electric process of steel making is especially adopted to
The unit cells
The iron ore in the charge of blast furnace acts as an iron bearing mineral.
Iron-carbon alloys containing 1.7 to 4.carbon are known as
The defect which takes place due to imperfect packing of atoms during crystallisation is known as