Glossary and Terms of the Foundry Industry

SFSA: Glossary of Terms - P

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P1: In production, the acceptable quality level.
P2: In production, lot tolerance.
Pack Hardening (Park Carburizing): See Case Harding
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 phosphate. 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 top layer of the mold is heated and 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 smoke.
Parting Agent: See Release Agent
Parting Line: A line on a pattern or casting corresponding to the separation between the cope and drag portions of a sand mold.
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: A form of wood, plastic, metal, or other material around which molding material is placed to make a mold.
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
Pearlite: A lamella aggregate of ferrite and carbide, the structure of pearlite can appear fine or coarse depending on processing.
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 expended 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; not an ingot mold. It is used repeatedly for the production of many casting of the same form.
pH: A symbol denoting the negative logarithm of the concentration of the hydrogen ion in gram-atoms per liter, used in expressing both acidity and alkalinity; pH=log 1/H per liter. An important factor in foundry sand control, pH7 is neutral; values less than 7 acid, and higher than 7, basic.
Phase Diagram: A graphic representation of the equilibrium temperature and composition limits of phase fields 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 aldehyde; used a binder for cores and sand molds.
See Urea-Form-aldehyde 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 alloys.
Physical Properties: For definitions of specific physical properties refer See
Picral: An etchant for ferrous alloys; 4% picric acid in alcohol.
Pig Iron, Basic: A grade of iron made from the basic open-hearth process of steelmaking; P, 0.40% max. for Northern iron, 0.70 to 0.90% for Southern iron; S 0.05% max. and Si, 1.50%.
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: Casting produced prior to the production run to verify correctness of procedures, materials, and process to be used in production.
Pipe: A cavity formed by shrinkage of the metal during solidification, usually occurring in a riser having feeder metal for the casting.
Pitting: A form of wear characterized by the presence of surface cavities, the formation of which is attributed to processes such as fatigue, local adhesion, cavitation or corrosion.
Plaster of Paris: A semi-hydrated form of calcium sulfate made by sintering gypsum to 120 - 130 C (248 - 266F).
Plane Strain: A stress condition in linear elastic fracture mechanics (See LEFM) in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth. Under plane strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress.
Plasma Refining: Process used to reduce sulfur and oxygen to very low levels.
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.
PMMA: Polymethymethacralate - Foam used in the lost foam process, does release as much carbon as polystyrene.
Pohland 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.
Polystyrene: A polymer of styrene used in making molding products. In particular, used in the lost foam process.
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 baked core cup placed on the 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. Generally used for cutting stainless steel.
Precipitation Hardening: A process of hardening an alloy in which a constituent precipitates from a supersaturated solid solution.
Precipition 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 crystal that form in an alloy during cooling below the liquidus temperature.
Process Capability: The amount of variation in the output of a controlled manufacturing process, the range defined by plus or minus three standard deviations.
Product Analysis: In castings, the analysis of the actual part as opposed to the analysis of the steel from which the casting was poured.
Production Welding: Any welding carried out during manufacturing before final delivery to the purchaser. This includes joint welding of casting and finishing welding.
Proeutectoid: The constituent that separates out of a solid solution before the formation of eutectoid.
Profile Tolerances: A system of locating and tolerancing developed to control the orientation of rough parts in machine fixtures. From locating points on the casting a " perfect profile " is established for all surfaces and features. A tolerance envelope surrounding that profile defines the limitations of an acceptable part.
Protection Tube: A metal, graphite, or ceramic tube which shrouds and protects the wires of a thermoelectric pyrometer.
psi: Pounds per square inch.
Pugnill: A mill for mixing foundry sands and sand mixtures consisting essential of a shaft fitted with plows or paddle wheel which revolve in a tub or vat.
Punchout Machines: A machine used to force the entire sand and casting contents from the molding box in one motion, without the use of vibration.
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 a 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 instruments.

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