Corrosion resistance of steel is increased by adding
Chromium and nickel
Nickel and molybdenum
Aluminium and zinc
Tungsten and sulphur
Correct Answer :
A. Chromium and nickel
Related Questions
Paramagnetic alpha iron changes to gamma iron at
770°C
910°C
1440°C
1539°C
Quenching is not necessary when hardening is done by
Case hardening
Flame hardening
Nitriding
Any one of these
In a hardening process, the hypo-eutectoid steel is
Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Carbon steel is
Made by adding carbon in steel
Refined from cast iron
An alloy of iron and carbon with varying quantities of phosphorus and sulphur
Extensively used for making cutting tools
The hardness of steel increases if it contains
Pearlite
Ferrite
Cementite
Martensite
In spheroidising process, the steel is
Heated below the lower critical temperature and then cooled slowly
Heated up to the lower critical temperature and then cooled in still air
Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
None of the above
The charge of the blast furnace consists of
Calcined ore (8 parts), coke (4 parts) and limestone (1 part)
Calcined ore (4 parts), coke (1 part) and limestone (8 parts)
Calcined ore (1 part), coke (8 parts) and limestone (4 parts)
Calcined ore, coke and limestone all in equal parts
Mild steel belongs to the following category
Low carbon steel
Medium carbon steel
High carbon steel
Alloy steel
Which of the following metal is used for nuclear energy?
Uranium
Thorium
Niobium
All of these
Iron-carbon alloys containing 1.7 to 4.3% carbon are known as
Eutectic cast irons
Hypoeutectic cast irons
Hypereutectic cast irons
None of these
Nimonic contains __________ percentage of nickel as that of Inconel.
Same
Less
More
None of these
Which is false statement about normalizing? Normalizing is done to
Refine grain structure
Reduce segregation in casting
Improve mechanical properties
Induce stresses
The maximum internal diameter of a blast furnace is about
3 m
6 m
9 m
12 m
Delta iron occurs at temperature of
Room temperature
Above melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
Cemented carbide tools are not found to be suitable for cutting
Brass
Cast iron
Aluminium
Steel
Permalloy is a
Kind of stainless steel
None ferrous alloy
Polymer
Nickel and iron alloy having high permeability
Which of the following alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
Corundum contains more than 95%
Steel
Al2O3
SiO2
MgO
Which of the following element results in presence of free graphite in C.I.?
Carbon
Sulphur
Silicon
Manganese
Cyaniding is the process of
Dipping steel in cyanide bath
Reacting steel surface with cyanide salts
Adding carbon and nitrogen by heat treatment of steel to increase its surface hardness
Obtaining cyanide salts
Cold rolled steel sheets contain carbon of the following order
0.1 %
0.2 %
0.4 %
0.6 %
Tin base white metals are used where the bearings are subjected to
Large surface wear
Elevated temperatures
Light load and pressure
High pressure and load
Elinvar, an alloy used in precision instruments, hair springs for watches, etc. contains the following element as principal alloying element
Iron
Copper
Aluminium
Nickel
By severely deforming a metal in a particular direction it becomes
Ductile
Malleable
Homogeneous
Anisotropic
The property of a material due to which it breaks with little permanent distortion, is called
Brittleness
Ductility
Malleability
Plasticity
The crystal structure of gamma iron is
Body centered cubic
Face centred cubic
Hexagonal close packed
Cubic structure
White metal contains
63 to 67% nickel and 30% copper
88% copper and 10% tin and rest zinc
Alloy of tin, lead and cadmium
Silver and chromium
Brass contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
Eutectoid reaction occurs at
600°C
723°C
1147°C
1493°C