P1: In production, the acceptable quality level.
P2: In production, lot tolerance.
Pack Hardening (Pack Carburizing): See Case Hardening.
Packing or Packing Material: Sand, gravel, mill scale, or similar materials used to support castings packed in annealing pots, to prevent possible
warpage under high temperatures.
Padding: The process of adding metal to a cross section of a casting wall, usually extending from a riser, to ensure adequate feed to a localized area
where a shrink would occur if the added metal were not present.
Panel Spalling Test: A test using a panel of the refractory being tested to provide a reference to spalling behavior.
Panoramic Analyzer: An instrument for analyzing sounds and displaying the results either on an oscilloscope or a graph.
Parkerizing: A proprietary method of producing a protective phosphate coating on ferrous metals. Parker A treatment involves immersing in a bath of acid manganese phos phate. The Parker D is a modification using acid zinc phosphate with a nitrate iron as accelerator.
Parlanti Casting Process: A proprietary permanent mold process using dies of aluminum with a controlled rate of heat transfer.
Parsons Duncan Process: A method of casting steel ingots wherein the too layer of the mold is heated and is the last to solidify.
Parted Pattern: A pattern made in two or more parts.
Partially Graphitized Cast Iron: A blackheart malleable casting only partly graphitized in annealing, giving a mixture of black and white. Sometimes termed salt and pepper fracture.
Particulate Matter: In air pollution control, solid or liquid particles, except water, visible with or without a microscope, that make up the obvious portion of smoke.
Parting Agent: See Release Agent.
Parting Line: 1. A line on a pattern or casting corresponding to the separation between the cope and drag portions of a sand mold, 2. mark left on
casting at joint.
Passivator: An inhibitor which changes the potential of a metal to a more cathodic value.
Passivity: The property of some metals to become abnormally inactive towards certain reagents.
Patching: Repair of a furnace lining; repair of a mold core.
Pattern Draft: The taper on vertical elements in a pattern which allows easy separation of pattern from compacted sand mixture.
Pattern Layout: Full-sized drawing of a pattern showing its arrangement and structure features.
Patternmaker: A craftsman engaged in production of foundry patterns from wood, plastic or metals, such as aluminum, brass, etc.
PCE: Pyrometric Cone Equivalent.
Peen: Peening action obtained by impact of metal shot, often used to improve fatigue properties by putting the surface in compression.
Pencil Core: A core projecting to the center of a blind riser allowing atmospheric pressure to force out feed metal.
Penetrameter: A strip of metal with stepped thickness variation and with holes at varying depths; used in radiography to indicate the sensitivity of the radiograph.
Penetration, Metal: Condition where molten metal has penetrated into the sand resulting in a mixture of metal and sand adhering to the casting.
Periclase: Natural magnesia in nodular form, formed by heating.
Perlite: A highly siliceous volcanic rock which can be expanded by heating into a porous mass of particles. Perlite can be used as an insulation in
foundry sand mixtures. Not to be confused with Pearlite.
Permanent Mold: A metal mold of two or more parts. It is used repeatedly for the production of many castings of the same form. Liquid metal is poured in by gravity, not an ingot mold.
Phase Diagram: A graphic representation of the equilibrium temperature and composition limits of phase fields and phase reactions in an alloy system. In a binary system, temperature is usually the ordinate and composition the abscissa. Ternary and more complex systems require several two-dimensional diagrams to show the temperature-composition variables completely. In alloy systems, pressure is usually considered constant, although it may be treated
as an additional variable.
Phenolic Resin (One-Step): A resin made by the polymerization of a phenol with an aidehyde; used as a binder for cores and sand molds.
See Urea-Formaldehyde Resin.
Photomicrograph: A photograph of the grain structure of a metal as observed when optically magnified more than 10 diameters. The term micrograph may be used.
Physical Metallurgy: The science concerned with the physical and mechanical characteristics of metals and a I alloys.
Picral: An etchant for ferrous alloys; 4% picric acid in alcohol.
Pig Iran, Basic: A grade of pig iron made for the basic openhearth process of steelmaking: P, 0.40% max for Northern iron, 0.70 to 0.90% for Southern iron; S, 0.05% max and and, 1.50% max.
Pig Iron, Chateaugay: Pig iron from Chateaugay (New York State) ores very low in phosphorus; copper-free and containing appreciable amounts of titanium.
Pilot Casting: A casting made from a production pattern to check accuracy of dimensions and quality of castings which will be produced from that pattern.
Pipe: A cavity formed by shrinkage of the metal during solidification, usually occurring in a riser having feeder metal for the casting.
Plaster of Paris: A semihydrated form of calcium sulfate made by sintering gypsum to 120-130 C (248-266 F).
Plastic Deformation: Permanent distortion of a material under the action of applied pressure.
Plates, Core Drying: Flat plates of metal on which cores are placed for baking.
Pohlman Method: A technique for the ultrasonic testing of steel in which a visible image of the defects present in the steel can be shown on a screen.
Postheating: A process used immediately after welding whereby heat is applied to the weld zone either for tempering or for providing a controlled rate of cooling, in order to avoid a hard or brittle structure.
Pouring: Transfer of molten metal from furnace to ladle, ladle to ladle, or ladle into molds.
Pouring Cup: The flared section of the top of the downsprue. It can be shaped by hand in the cope, or be a shaped part of the pattern used to form the
downsprue; or may be a baked core cup placed on top of the cope over the downsprue.
Powder Cutting: Introducing iron powder in an oxygen stream to hasten oxygen torch cutting by the combination of fluxing and oxidation.
Precipitation Hardening: A process for hardening an alloy in which a constituent precipitates from a supersaturated solid solution.
Precipitation Heat Treatment: Any of the various aging treatments conducted at elevated temperatures to improve certain mechanical properties through precipitation from solid solution.
Preheating: A general term for heating material, as a die in die casting, as a preliminary to operation, to reduce thermal shock and prevent adherence of molten metal.
Pressure Die Casting: A British term. See Die Casting.
Pressure-Tight: A term describing a casting free from porosity of the type that would permit leaking.
Primary Choke (Choke): That part of the gating system which most restricts or regulates the flow of metal into the mold cavity.
Primary Crystals: The first dendritic crystals that form in an alloy during cooling below the liquidus temperature.
Proeutectoid: The constituent that separates out of of a solid solution before the formation of eutectoid.
Protection Tube: A metal, graphite, or ceramic tube which shrouds and protects the wires of a thermoelectric pyrometer.
psi: Pounds per square inch.
Pugmill: A mill for mixing foundry sands and sand mixtures consisting essentially of a shaft fitted with plows or paddle wheels which revolve in a tub or vat.
Purging: Elimination of air and other undesirable gases from furnaces or heating boxes.
Pyrometallurgy: Chemical metallurgical process dependent upon heat.
Pyrometric Cone: A slender trihedral pyramid made of a mixture of minerals similar in composition to that of the clay or other refractory being tested.
Each cone is assigned a number indicating its fusion temperature.
Pyrometric Cone Equivalent (PCE): An index of refractoriness obtained by heating on a time-temperature schedule a cone of the sample material
and a series of standardized pyrometric cones of increasing refractoriness.
Pyrometry: A method of measuring temperature with any type of temperature indicating instrument.