Case Hardening or Carburizing of steel

It is diffusing carbon into surfaces of steel components. This is done when a component should be hard on the outer face but tough inside.

Ferrite, Cementite, Pearlite & Austenite

alpha-Iron is Ferrite
Fe3C - Cementite
Ferrite + Cementite is Pearlite
Gamma-phase Iron is Austenite

Subcooled Liquid or Compressed Liquid

If the temperature of the liquid is lower than the saturation temperature for the existing pressure,it is called either a subcooled liquid (implying that the temperature is lower than the saturation temperature for the given pressure) or a compressed liquid (implying that the pressure is greater than the saturation pressure for the given temperature).

Triple Point & Critical Point

The point where the three lines(sublimation, fusion and vaporization line) meet is called the triple point. The triple point is the only point at which all three phases can exist in equilibrium. 

The point where the vaporization line ends is called the critical point.

Sublimation, Vaporization, Condensation and Fusion or Melting

Sublimation - change of phase from solid to vapor

Vaporization - change of phase from liquid to vapor

Condensation - change of phase from vapor to liquid

Fusion or melting - change of phase from solid to liquid

Critical Point

Critical Point:- The temperature and pressure above which there is no distinction between the liquid and vapor phases.

Comparative, or object, pronouns

Comparative, or object, pronouns are used in place of the object of the verb.

Charles' Law

The pressure of a gas varies directly with temperature when the volume is held constant, and the volume varies directly with temperature when the pressure is held constant.

Crossover (Boiler)

The interconnecting piping between any two heater coil sections.

Corrosion Rate

The reduction in the material thickness due to the chemical attack from the process fluid or flue gas or both, expressed in mils per year or millimeters per year.

Corrosion Allowance

The additional metal thickness added to allow for metal loss during the design life of the component.   It is the corrosion rate multiplied by the tube design life, expressed in inches or millimeters.

Corbel

A projection from the refractory surface generally used to prevent flue gas bypassing the convection section tubes.

Convection Section

The portion of the heater in which the heat is transferred to the tubes primarily by convection.

Chelate

An organic compound used in boiler water treatments which bonds with free metals in solution.  Chelates help prevent metals from depositing upon tube surfaces.

Ceramic Fiber

A fibrous refractory insulation composed primarily of silica and alumina (and sometimes zirconia) that can

comes in various forms like blanket, board, module, rigidized blanket, and vacuum-formed shapes.