Ferrous Metals

Electrode

A device that conducts electricity. In welding, the ________ also can act as the filler metal.

Gas Torch

A device that emits heat in the form of a gas. ________ torches are used to preheat base metals.

Arc Welding

A fusion welding process that uses electricity to generate the heat needed to melt the base metals.

Hydrogen

A gas that is the lightest and most abundant element in the universe. Too much ________ near the weld metal can cause cracking.

Magnesium

A grayish white, extremely light metal that is also brittle and has poor wear resistance.

Manganese

A hard, brittle, gray-white metal that increases the hardenability of steel. ________ also increases strength and hardness.

Nickel

A hard, malleable, silvery white metal used in ferrous alloys to add strength, toughness, and impact resistance to steel.

Alloy

A metal consisting of a mixture of two or more materials. One of these materials must be a metal.

Steel

A metal consisting of iron and carbon, usually with small amounts of other elements. ________ is the most common manufacturing metal.

Ferrous Metal

A metal that contains iron. Steel is the most popular ________ metal.

Nonferrous Metal

A metal that does not contain iron. Aluminum and copper are common ________ metals.

Ductility

A metal's ability to be drawn, stretched, or formed without breaking.

Strength

A metal's ability to resist outside forces that are trying to break or deform the metal.

Toughness

A metal's ability to withstand a sharp blow without breaking.

Molybdenum

A metallic alloying element commonly used to increase hardenability in carbon and alloy steels and to enhance corrosion resistance in stainless steels.

Weld

A mix of metals that joins at least two separate parts. ________ can be produced by applying heat, or pressure, or both heat and pressure, and they may or may not use an additional filler metal.

Chromium Oxide

A protective film that develops on the surface of stainless steel and helps prevent corrosion.

Copper

A reddish metal that is very ductile, thermally and electrically conductive, and corrosive resistant. ________ is often used to make electrical wire.

Chromium

A shiny, hard, steel-gray metal that increases the hardenability and corrosion resistance of steel. Stainless steels also contain large amounts of ________ .

Aluminum

A silvery white metal that is soft, light, and an effective conductor.

Alloy Steel

A steel that contains intentionally added materials, which change the property of the metal. Common ________ elements include chromium, manganese, molybdenum, and nickel.

Carbon Steel

A steel that is made up of iron and carbon, without any additional materials.

Stainless Steel

A type of steel that contains more than 15% chromium and exhibits excellent corrosion resistance.

Gas Tungsten Arc Welding

A very precise arc welding process that uses a nonconsumable tungsten electrode. It is also referred to as GTAW or TIG welding.

Joint

The meeting point of the two materials that are joined together. Welding creates a permanent ________ .

Joint Penetration

The minimum depth that a groove weld extends into the face of a joint.

Heat-Affected Zone (HAZ)

The portion of the base metal that has not been melted but with mechanical properties have been altered by the heat of welding.

Mechanical Properties

The properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break.

Physical Properties

The properties that describe a material's ability to melt, emit heat, conduct electricity, and expand or shrink.

Thermal Conductivity

The rate at which heat flows through metal.

Weldability

The ability of a material to be welded under imposed conditions into a specific, suitable structure and to perform satisfactory for its intended use.

Hardenability

The ability of a metal to be hardened by normal heat treatment processes.

Electrical Conductivity

The ability of a metal to conduct an electrical current.

Corrosion Resistance

The ability of a metal to resist attack by other elements and chemicals.

Tensile Strength

The ability of a metal to resist forces that attempt to pull apart or stretch it.

Compressive Strength

The ability of a metal to resist forces that attempt to squeeze or crush it.

Hardness

The ability of a metal to resist indentation, penetration, and scratching. The heat from welding may change a metal's ________ .

Yield Strength

The ability of a metal to tolerate gradual progressive force without permanent deformation.

Preheating

The application of heat to a base metal immediately before welding. ________ helps reduce hardness in the metal.

Post Heating

The application of heat to the weld immediately after welding. ________ ________ helps reduce stress in the weld metal.

Heat Treatment

The controlled heating and cooling processes used to change the structure of a material and alter its physical and mechanical properties.

Grain Growth

The expansion of the individual crystals in a metal. ________ ________ results in a loss of toughness.

Iron

The fourth most abundant earth element. ________ is alloyed with carbon to make steel.

Corrosion

The gradual chemical attack on a metal by atmosphere, moisture, or other agents.

Thermal Expansion

The increase in the dimensions of a metal due to an increase in its temperature.

Crystal Structure

The regular, repeating pattern of atoms in a metal. ________ ________ develop as a metal solidifies.

Grain Structure

The relationship between the small, individual crystals in a metal or alloy.

Melting Temperature

The temperature necessary to change a metal from solid to a liquid. Also known as melting point.

Distortion

Warpage in the base metal due to stresses caused by heating it to expansion and then cooling it to contraction.

Carbon

A common, non-metallic element found in all types of steel. ________ is the main hardening element in steel.

Medium-Carbon Steel

A carbon steel that contains between 0.30% and 0.45% carbon. These steels are strong, hard, and not as easily welded as low-carbon steels.

Low-Carbon Steel

A carbon steel that contains less than 0.30% carbon. These steels are generally tough, ductile, and easily welded.

High-Carbon Steel

A carbon steel that contains more than 0.5% carbon. These steels are extremely strong, hard, and always require heat treatment for effective welding.

Properties

A characteristic of a material that distinguishes it from other materials.

Oxygen

A colorless, odorless, tasteless gas that naturally exists in the atmosphere. In welding, too much ________ causes cracking and rusting in the metals.

Gas Metal Arc Welding

An arc welding process in which the bare wire electrode and inert shielding gas are fed to the weld through a welding gun. It is also referred to as GMAW or MIG welding.

Shielded Metal Arc Welding

An arc welding process that uses a flux-coated rod. It is also referred to in the shop as SMAW or stick welding.

Mild Steel

Another name for low-carbon steel.

Porosity

Cavity type discontinuities or bubbles formed by gas entrapment during solidification of the weld metal.

Base Metal

One of the two or more metals to be welded together to form a joint.

Internal Porosity

Porosity that occurs within a particular metal.

Ferritic Stainless Steel

Stainless steel that contains mostly chromium and has low carbon content. ________ stainless steels are easy to weld and not hardenable by heat treatment.

Martensitic

Stainless steel that is stronger than ferritic stainless steel but less corrosion resistant. ________ stainless steels are hardenable by heat treatment.

Austenitic Stainless Steel

Stainless steel with very high strength, as well as excellent ductility and toughness. ________ stainless steel is the most corrosion resistant stainless steel.