U

Ultimate Analysis
The ultimate of a coal expressed in terms of carbon, hydrogen, nitrogen, sulphur and oxygen. The analysis refers to the carbonaceous material only and hence is often expressed on a dry ash free basis or dry mineral matter free basis. Oxygen is generally estimated by difference although there are methods for its determination.
 

V

Vanadium increases the yield strength and the tensile strength of carbon steel. The addition of small amounts of Vanadium can significantly increase the strength of steels. Vanadium is one of the primary contributors to precipitation strengthening in microalloyed steels. When thermomechanical processing is properly controlled the ferrite grain size is refined and there is a corresponding increase in toughness. The impact transition temperature also increases when vanadium is added.

W

WALE: 1. In knit fabrics, a column of loops lying lengthwise in the fabric. The number of wales per inch is a measure of the fineness of the fabric.

WARP: 1. The set of yarn in all woven fabrics, that runs lengthwise and parallel to the selvage and is interwoven with the filling.

WATERPROOF: A term applied to materials that are impermeable to water; waterproof fabrics have had all their pores closed and are also impermeable to air and very uncomfortable.

WATER-REPELLENT: A term applied to fabrics that can shed water but are permeable to air and comfortable to wear. These fabrics are produced by treating the material with a resin, wax, or plastic finish that is not completely permanent.

WEFT - In woven fabric, the filling yarns that run perpendicular to the warp yarns.

WATER HARDENING - High carbon grades of tool steel, straight carbon steels and low alloy steels that are hardened by quenching in water during the heat treating operation.

X

Y

YARN: A generic term for a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric. Yarn occurs in the following forms: (1) a number of fibers twisted together (spun yarn); (2) a number of filaments laid together without twist (a zero-twist yarn); (3) a number of filaments laid together with a degree of twist; (4) a single filament with or without twist (a monofilament); or (5) a narrow strip of material, such as paper, plastic film, or metal foil, with or without twist, intended for use in a textile construction.
 

Z

Zirconium can be added to killed high-strength low-alloy steels to achieve improvements in inclusion characteristics. Zirconium causes sulfide inclusions to be globular rather than elongated thus improving toughness and ductility in transverse bending.