Modified Basic Oxygen Furnace in which the oxygen and other gases are blown in
from the bottom, rather than from the top. While the Q-BOP stirs the metal bath
more vigorously, allowing for faster processing, the design produces essentially
the same steel grades as the top-blowing basic oxygen furnace. Today's
state-of-the-art furnace design combines the previous technologies: 60% of the
oxygen is blown from above, with the rest blown through the bottom of the
A term used to denote the
degree of perfection of the steel sheet. Often, for sheet
products, relative quality refers to the degree of
perfection of the surface, i.e., the lack of scratches,
absence of slivers, etc. Quality can also refer to other
attributes such as internal soundness, dimensional control,
The testing required for a new process adopted to make certain grades of steel
with exacting end uses. In order for the process to become qualified, the steel
made by the process must be tested.
Quarter Hard (No. 3 Temper)
(A) In low carbon cold-rolled strip steel, a
medium soft temper produced by a limited amount of cold rolling after annealing.
(B) In brass mill terminology. Quarter hard is one B and S number hard or 10.95%
reduction. (C) In stainless steel terminology tempers are based on minimum
tensile, or yield strength. For Chromium-Nickel grades Quarter Hard Temper is
125,000 T. S., 75,000 Y.S. min.
Aging that occurs after quenching following
solution heat treatment.
Hardening a ferrous alloy by austenitizing
and then cooling rapidly enough so that some or all of the austenite transforms
to martensite. The austenitizing temperature for hypoeutectoid steels is usually
above Ac3 and for hypereutectoid steels usually between Ac1 and Ac (cm).
Quench Hardening (Steel)
A process of hardening a ferrous alloy of
suitable composition by heating within or above the transformation range and
cooling at a rate sufficient to increase the hardness substantially. The process
usually involves the formation of martensite.
In the heat treating of metals, the step of cooling metals rapidly in order to
obtain desired properties; most commonly accomplished by immersing the metal in
oil or water. In the case of most copper base alloys, quenching has no effect
other than to hasten cooling.