Black Plate |
(english) A light weight or a thin uncoated steel sheet or strip so called because of its dark oxide coloring prior to pickling. It is manufactured by two different processes. (1) Form sheet bar on single stand sheet mills or sheet mills in tandem. This method is now almost obsolete. (2) On modern, high speed continuous tandem cold reduction mills from coiled hot rolled pickled wide strip into ribbon wound coils to finished gage. Sizes range from 12 to 32 in width, and in thicknesses from 55 lbs. to 275 lbs. base box weight. It is used either as is for stampings, or may be enameled or painted or tin or terne coated. |
Blacking Hole |
(english) Irregular-shaped surface cavities in a casting containing carbonaceous matter. Caused by spilling off of the blacking from the mold surface. |
Blast Cleaning (blasting) |
(english) A process for cleaning or finishing metal objects by use of an air jet or centrifugal wheel that propels abrasive particles (grit, sand, or shot) against the surfaces of the workpiece at high velocity. |
Blast Furnace |
(english) 1) A furnace in which solid fuel (limestone, coke, iron ore) is combined with high-pressure, hot air blast (120,000 psi) to smelt ore in a continuous process (They are never stopped. They can be slowed down or idled). A Blast Furnace in the iron and steel industry is used to produce liquid iron. |
Blast Furnace 2 |
(english) A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pih iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals. |
Blasting (Blast Cleaning) |
(english) A process for cleaning or finishing metal objects by use of an air blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Small, irregular particles of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting. |
Bleeder |
(english) A defect wherein a casting lacks completeness due to moltn metal draining or leaking out of some part of the mold cavity after pouraing has stopped. |
Blister |
(english) 1) Coating defect consisting of the formation of bubbles in a coating, which appear as hemispherical elevations. The blisters are hollow, and are usually caused by entrapped air or solvent. 2) A raised spot on the surface on the surface of metal due to expansion of gas which causes a subsurface metal separation such as inclusions and small laminations. |
Blow Back |
(english) A coating defect consisting of a lower coating film weight on the bottom of the coated sheet caused by high velocity air in the oven. Blow back usually occurs with high solids coatings which have little solvent to evaporate and "set" the film. |
Blow Down |
(english) Process that rids boiler feed water of solids and maintains the proper chemical balance of the feed water. Blow down can also be used to rid drum(s) of excess water. |