|
|
Radiography
A non-destructive method in internal examination. Metal objects are exposed to x-rays or gamma radiation.
Recrystalization
A process where distorted grain structures in cold worked metal is replaced by new, stress free grain structures by certain annealing processes.
Refining Temperatures
A temperature used in heat treatment of steel to refine the structure and grain size.
Refractory
A heat resistant material, usually non metalic, which is used for furnace lining.
Refractory Alloy
Metal with extremely high melting point.
Residual Stress
Macroscopic stresses that are set up within a metal as a result of non-uniform plastic deformation.
Residuals
The "trace" elements not named in specifications. They are the result of contaminated scrap.
Ribbon Wound
Strip wound layer on top of layer... as a roll of tape. This type of rolling is done around a core.
Ripple
Defect. Slight traverse wave or shadow appearing at intervals along the strip or sheet.
Rockwell Hardness
A standard method of measuring hardness. It is a measurement of penetration under specific load.
Rolled Edge
The deburring of an edge by a system of rollers which shape the edge of the material.
Rotary Shear
A cutting machine with sharpened circular blades. A slitter.
|
|
|
|
|
Salt Fog (Spray) Test
A corrosion test in which the metal is subjected to a fine mist of salt water.
Scab
A blemish on a casting.
Scaling
(1) Layers of oxidation. (2) The removal of scale from metal.
Scalping
The surface matching of surface layers of ingots, billets, and slabs before machining.
Scarfing
Cutting or grinding out defects from ingots, billets, or the edges of plates that are to be beveled for butt welding.
Scleroscope Hardness Test
A hardness test in which a diamond pointed hammer is dropped onto metal and the height of the bounce it's measured.
Screw Stock
Free machining bar rod or wire.
Skelp
A piece or strip of metal produced to a suitable thickness, with an edge from which pipe or tubing is made.
Seam
Defect. A crack on the surface of metal that has been closed, but not welded. It is caused in casting or working.
Seconds
A designation given to material that has surface defects. Material of less than prime quality.
Secondary Hardening
Tempering certain alloy steels at certain temperatures so that the resulting hardness is greater than that obtained by tempering the same steel at some lower temperature for the same time.
Segregation
Non-uniform distribution of alloying elements, impurities or micro-phases.
Shear
A machine for cutting steel.
Shear Strength
The stress required to produce fracture in the plain of a piece of metal.
Shear Crack
A crack or fracture caused by shear stress.
Shim
A thin (hard) flat metal used for tool, die and machine alignment purposes.
Shore Hardness Test
- See Scleroscope Hardness Test.
Short
Brittle.
Shortness
A form of brittleness in metal. It is designated as a "cold," "hot," and "red" to indicate the temperature range in which the brittleness occurs.
Silky Fracture
A very smooth fine grain silky appearing fracture.
Silver Solders
Alloys of silver, copper, zinc and other metals used for making strong yet moderately ductile joints that resist corrosion.
Sintering
Converting metal powder into a mass by heating after compressing.
Skin
A thin surface layer that is different from the main mass of metal in composition, structure or other characteristics.
Slab
- See Bloom
Slit Edge
The edge resulting from a slitting operation.
Sliver
Defect: loose metal piece rolled into the surface of the metal during the rolling operation.
Slug
A metal blank for forging or impacting.
Soaking
Prolonged heating of metal at selected temperatures.
Solid Solution
A single solid homogeneous crystaline phase containing two or more chemical species.
Solution Heat Treatment
Heating an alloy to a suitable temperature, holding at that temperature long enough to allow one or more constituents to enter into solid heating solutions.
Sorbite
Structure of steel, resulting from the tempering of martensite.
Spalling
The cracking and flaking of particles of a surface.
Specific gravity
A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water.
Spherodizing
Heating and cooling to produce a spherical or globular form of carbon in steel.
Stabilizing Treatment
A thermal process intended to stabilize the structure of an alloy or dimensions of a part.
Stainless Steel
Corrosion resistant steel in a wide variety of types, but always containing a large amount of chromium.
Stamping
A term used to refer to various press forming operations in coining, embossing, blanking and pressing.
Sticker
The adhering of steel sheet or strip, usually caused by overheating during box annealing.
Strain
Deformation produced on a body by an outside force.
Strain Aging
Aging induced by cold working. See Aging.
Strain Hardening
An increase in hardness and strength caused by plastic deformation at lower than the recrystalization range.
Stress Relieving
Heating to a suitable temperature holding long enough to reduce residual stresses and then cooling slowly enough to minimize developing new residual stresses.
Stretch Forming
Forming panels and cowls of large curvature by stretching sheet over a form of desired shape. This is more rapid than hammering and beating.
Stretcher Leveling
Leveling sheets of metal by gripped at both ends and stretched beyond its yield strength.
Stretcher Strains
Elongated markings on the surface that appear when deformed just passed the yield point.
Structure
The arrangement of parts: in crystals, especially, the shape and dimension of the unit cell, and the number, kinds positions of the atoms within eat.
Suck-In
A defect caused when one phase of a forging is sucked-in to fill in a projection on the opposite site.
Superalloy
An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory and shock) are encountered and where oxidation resistance is frequently required.
|
|
