Caused by cracks in the surface of a roll used for hot rolling, they are a particular form of roll mark.

Equipment used to bring down the temperature of spent sulfuric acid for the removal of iron. This process produces a by-product called ferrous sulfate crystal.

The rapid cooling of a heated metal through its transformation range to promote hardening that is done by a controlled immersion in oil, water, molten salt or lead at a specific temperature.

A scoring device used in the wire shaving operation to facilitate the separation of the outer skin of shaved wire.

A method for removing seams and other surface defects with a chisel or gouge so that such defects will not be worked into the finished product. Removal of defects by gas cutting is known as “de-seaming” or “scarfing.” Machining away the surface on the main faces of a billet to remove faults, which would give rise to unsatisfactory products in the final stages of rolling and drawing. Also known as “scalping.”

1) The roasting of prepared ore in contact with a chloride, usually common salt, to convert certain metals into the more easily separated chloride. 2) The degassing or purification of molten metals by fluxing with chlorine.

This vulcanizable material has good electrical properties and exceptional resistance to ozone. As a jacket material, it is suitable for cables subject to abuse and severe handling conditions. Manufactured by Dupont under the tradename of Hypalon.

The initials “FXT” stand for Christmas tree wire, a fixture wire for carrying current that will not cause the temperature of the wire to exceed 60°C.

A conversion coating produced on galvanized material in baths containing either chromic acid or dichromates in combination with organic or inorganic compounds which act as catalysts.

A ceramic coating applied to drawing capstans and blocks to increase wear resistance.

A chemical treatment for magnesium in a nitric acid, sodium dichromate solution. The treatment gives some protection against corrosion by producing a film that is also a base for paint.

A chemical reaction sometimes occurring at welding of austenitic stainless steels, containing more than 0.05% C. At the high temperature, a chromium-iron carbide is formed. Chromium, near the boundaries of the grains, flows to the boundaries and unites with carbon, thus depleting the chromium supply in the metal near the grain boundaries. The alloy loses its corrosion resistance as the grain boundaries are attacked in acid water solutions. The attack is called intergranular corrosion, which in turn can cause severe damage from mild agents that are not at all expected to attack stainless steels.

The alloys used in making Chromel® Alumel® thermocouple wires. Chromel is an alloy of nickel and chrome plus nine other elements. Alumel is an alloy containing nickel manganese, aluminum, silicon and nine other elements. Chromel is the positive wire; Alumel is the negative. Chromel and Alumel are registered trademarks of the Hoskins Mfg. Co.

Element, chemical symbol Cr. This alloying material, which helps form ferrite and improves hardenability, is very easy to passivate. A thin yet dense oxide layer with good adherence is spontaneously formed on the metal surface in contact with air. This passive layer provides improved wet corrosion and high temperature attack. A steel alloyed with more than 12% chromium is classified as a stainless steel, which itself can be influenced by other alloying elements, especially nickel, molybdenum and carbon. The chromium steel, however, has no resistance to diluted non-oxidizing acids such as sulfuric acid and hydrochloric acid. See entries for Chromium Plating and Passivate.

Copper containing from 0.4 to 0.8 percent chromium. Can be hardened and strengthened by heat treatment and has a conductivity upwards of 80 percent I.A.C.S.

During production of stainless wire rod, an oxide layer is formed on its surface. This scale is richer in chromium than the steel it is formed on, which leads to a chromium depletion in the rod’s metallic surface region. Both scale and the depleted zone have to be removed during pickling.

Stainless steel wires have excellent welding characteristics, the 18 percent chromium, 8 percent nickel alloy being most widely used. The 25 percent chromium, 12 percent nickel quality, in addition to being highly resistant to corrosion, also has wide uses because it has exceptional resistance to scaling at temperatures up to 2120°F (1150°C).

This scale on stainless steel wire and rod is impervious to acid attack, and can only be eliminated by mechanical abrasion methods such as grinding (or, if not too severe, by hand rubbing with a wire brush). Formation of chromium oxides during heat treatment of chromium-nickel steels is very difficult to avoid, due to the strong affinity between chromium and oxygen.

Used for a hard deposit for engineering purposes or in conjunction with nickel to produce a decorative/protective finish. Hard chromium is applied directly to the basis metal to create a surface that is extremely hard, highly resistant to abrasion, has an extremely low co-efficient of friction and good anti-seize properties.

A low-alloy steel of this type is sometimes used for springs, an approximate composition being 1 percent chromium, 1 percent silicon and 0.40 percent carbon.