Ferrous metallurgy

In Europe, the Iron Age is the last stage of the prehistoric period and the first of the protohistoric periods, which initially meant descriptions of a particular area by Greek and Roman writers. For much of Europe, the period came to an abrupt end after conquest by the Romans, though ironworking remained the dominant technology until recent times. Elsewhere, the period lasted until the early centuries AD, and either Christianization or a new conquest in the Migration Period.Iron working was introduced to Europe in the late 11th century BC, probably from the Caucasus, and slowly spread northwards and westwards over the succeeding 500 years. For example, the Iron Age of Prehistoric Ireland begins around 500 BC, when the Greek Iron Age had already ended, and finishes around 400 AD. The use of iron and iron-working technology became widespread concurrently in Europe and Asia.

The start of the Iron Age is marked by new cultural groupings, or at least terms for them, with the Late Bronze Age Mycenaean Greece collapsing in some confusion, while in Central Europe the Urnfield culture had already given way to the Hallstatt culture. In north Italy the Villanovan culture is regarded as the start of Etruscan civilization. Like its successor La Tène culture, Hallstatt is regarded as Celtic. Further to the east and north, and in Iberia and the Balkans, there are a number of local terms for the early Iron Age culture. Roman Iron Age is a term used in the archaeology of Northern Europe (but not Britain) for the period when the unconquered peoples of the area lived under the influence of the Roman Empire.

In materials science, a refractory (or refractory material) is a material that is resistant to decomposition by heat or chemical attack and that retains its strength and rigidity at high temperatures. They are inorganic, non-metallic compounds that may be porous or non-porous, and their crystallinity varies widely: they may be crystalline, polycrystalline, amorphous, or composite. They are typically composed of oxides, carbides or nitrides of the following elements: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. Many refractories are ceramics, but some such as graphite are not, and some ceramics such as clay pottery are not considered refractory. Refractories are distinguished from the refractory metals, which are elemental metals and their alloys that have high melting temperatures.

Refractories are defined by ASTM C71 as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above 1,000 °F (811 K; 538 °C)". Refractory materials are used in furnaces, kilns, incinerators, and reactors. Refractories are also used to make crucibles and molds for casting glass and metals. The iron and steel industry and metal casting sectors use approximately 70% of all refractories produced.

Pig iron, also known as crude iron, is an intermediate good used by the iron industry in the production of steel. It is developed by smelting iron ore in a blast furnace. Pig iron has a high carbon content, typically 3.8–4.7%, along with silica and other dross, which makes it brittle and not useful directly as a material except for limited applications.

Cementite (or iron carbide) is a compound of iron and carbon, more precisely an intermediate transition metal carbide with the formula Fe₃C. By weight, it is 6.67% carbon and 93.3% iron. It has an orthorhombic crystal structure. It is a hard, brittle material, normally classified as a ceramic in its pure form, and is a frequently found and important constituent in ferrous metallurgy. While cementite is present in most steels and cast irons, it is produced as a raw material in the iron carbide process, which belongs to the family of alternative ironmaking technologies. The name cementite originated from the theory of Floris Osmond and J. Werth, in which the structure of solidified steel consists of a kind of cellular tissue, with ferrite as the nucleus and Fe₃C the envelope of the cells. The carbide therefore cemented the iron.

The Chalybes (/ˈkælɪbiːz/; Ancient Greek: Χάλυβες/Χάλυβοι; Georgian: ხალიბები) and Chaldoi (Ancient Greek: Χάλδοι; Armenian: Խաղտիք, romanized: Xałtik') were peoples mentioned by classical authors as living in Pontus and Cappadocia in northern Anatolia during Classical Antiquity. Their territory was known as Chaldia, extending from the Halys River to Pharnakeia and Trabzon in the east and as far south as eastern Anatolia. According to Apollonius of Rhodes, the Chalybes were Scythians.

The Chaldoi, Chalybes, Mossynoikoi, and Tibareni, are counted among the first ironsmith nations by classical authors. Χάλυψ, the tribe's name in Ancient Greek, means "tempered iron, steel", a term that passed into Latin as chalybs, "steel". Sayce derived the Greek name Chalybe from Hittite Khaly-wa, "land of Halys River". More than an identifiable people or tribe, "Chalybes" was a generic Greek term for "peoples of the Black Sea coast who trade in iron" or "a group of specialised metalworkers".