HIST363: Global Perspectives on Industrialization

Alloy steels were known from antiquity, being nickel-rich iron from meteorites hot-worked into useful products. In a modern sense, alloy steels have been made since the invention of furnaces capable of melting iron, into which other metals could be thrown and mixed.

Historic types

• Damascus steel – famous in ancient times for its durability and ability to hold an edge, it was created from a number of different materials (some only in traces), essentially a complicated alloy with iron as main component
• Blister steel – steel produced by the cementation process
• Crucible steel – steel produced by Benjamin Huntsman's crucible technique
• Styrian steel – also called 'German steel' or 'Cullen steel' (being traded through Cologne), was made in the Styria in Austria (Roman province of Noricum) by fining cast iron from certain manganese-rich ores
• Shear steel – blister steel that was broken up, faggotted, heated and welded to produce a more homogeneous product

Contemporary steel

• Carbon steel is composed simply of iron and carbon accounts for 90 percent of steel production.
• HSLA steels (high strength, low alloy) have small additions (usually less than two percent by weight) of other elements, typically 1.5 percent manganese, to provide additional strength for a modest price increase.
• Low alloy steel is alloyed with other elements, usually molybdenum, manganese, chromium, or nickel, in amounts of up to ten percent by weight to improve the hardenability of thick sections.
• Stainless steels and surgical stainless steels contain a minimum of ten percent chromium, often combined with nickel, to resist corrosion (rust). Some stainless steels are nonmagnetic.
• Tool steels are alloyed with large amounts of tungsten and cobalt or other elements to maximize solution hardening, allow precipitation hardening and improve temperature resistance.
• Cor-ten and related steels weather by acquiring a stable, rusted surface, and so can be used unpainted.
• Advanced high strength steels
  • Complex phase steel
  • Dual phase steel
  • TRIP steel
  • TWIP steel
  • Maraging steel
  • Eglin steel
• Ferrous superalloys
• Hadfield steel (after Sir Robert Hadfield) or manganese steel, this contains 12 to 14 percent manganese which when abraded forms an incredibly hard skin which resists wearing. Some examples are tank tracks, bulldozer blade edges and cutting blades on the jaws of life.

Though not an alloy, there exists also galvanized steel, which is steel that has gone through the chemical process of being hot-dipped or electroplated in zinc for protection against rust. Finished steel is steel that can be sold without further work or treatment.

Modern steel

• TMT Steel (thermo-mechanically treated steel) is one of the latest developments in the history of steel. The steel manufacturing process is improved and thereby the properties of this steel to suit RCC construction work has been achieved. The steel wires are passed through cold water just after drawing from the extruder. This helps in rapid cooling of the skin and heat starts flowing from the center to the skin once the wire is out of the water. This acts as a heat treatment. The relatively soft core helps in ductility of the steel while the treated skin has good weldability to suit construction requirements.