An oxide of iron which forms on the surface of hot steel. Sometimes it forms in large sheets which fall off when the steel is rolled.
Cutting surface areas of metal objects, ordinarily by using a gas touch. The operation permits surface defects to be cut from ingots, billets, or the edges of plate that is to be beveled for butt welding.
SCHEDULE NUMBERS :
ANSI numbers assigned to pipe depending upon wall thickness (Becoming obsolete).
A crack caused by a blowhole or other defect which has been closed but not welded.
SEAM ANNEALED :
Heating a weld seam to a temperature slightly below the point at which grain structure is effected (known as the critical temperature), followed by cooling in still air. This reduces weld hardness without changing the grain structure.
SELF-HARDENING STEEL :
An alloy tool steel that hardens when cooled in air and which will hold a cutting edge at temperatures nearing a light red.
Steel of an intermediate carbon range between iron and steel.
SHORE HARDNESS :
The reading of a conventional scale determined by the rebound of the hammer of the Shore scleroscope on striking the surface of the specimen.
Steel that is the entry material to a pipe mill. It resembles hot-rolled strip, but its properties allow for the severe forming and welding operations required for pipe production.
The most common type of semi-finished steel. Traditional slabs measure ten inches thick and 30-85 inches wide (an average about 20 feet long), while the output of the recently developed "thin-slab" casters is approximately two inches thick. Subsequent to casting, slabs are sent to the hot-strip mill to be rolled into coiled sheet and plate products.
Holding steel at fixed temperature long enough for a complete uniform penetration of the heat.
SOLIDIFICATION RANGE :
Temperature at which metal solidifies.
Cracking and flaking of the metal surface.
Prolonged heating of iron base alloys at a temperature in the neighborhood of, but generally slightly below, the critical temperature range, usually followed by relatively slow cooling.
Note a — In the case of small objects of high carbon steels, the spheroidizing result is achieved more rapidly by prolonged heating to temperatures alternately within and slightly below the critical temperature range.
Note b — The object of this heat treatment is to produce a globular condition of the carbide.
Paint spray identification placed on pipe. Specification, size, wall, grade, test pressure, method of manufacture and normal mill characters and mill identification are usually included; however, detail varies by specification. “Made in USA” is included.
STRESS RELIEVING :
A process of reducing residual stresses in a metal object by heating the object to a suitable temperature and holding for a sufficient time, and cooling slowly. This treatment may be applied to relative stresses induced by casting, quenching, normalizing, machining, cold working or welding.
STRETCH REDUCTION :
Property of absorbing considerable energy before fracture; usually represented by the area under a stress-strain curve, and therefore involving both ductility and strength.