Wrought iron no relation slag inclusions
Properties
The slag inclusions, or stringers, in wrought iron give it properties not found in other forms of ferrous metal. There are approximately 250,000 inclusions per square inch.  A fresh fracture shows a clear bluish color with a high silky luster and fibrous appearance.
Wrought iron lacks the carbon content necessary for hardening through heat treatment, but in areas where steel was uncommon or unknown, tools were sometimes cold-worked (hence cold iron) to harden them. An advantage of its low carbon content is its excellent weldability.  Furthermore, sheet wrought iron cannot bend as much as steel sheet metal when cold worked. Wrought iron can be melted and cast, however the product is no longer wrought iron, since the slag stringers characteristic of wrought iron disappear on melting, so the product resembles impure, cast, Bessemer steel. There is no engineering advantage as compared to cast iron or steel, both of which are cheaper.Due to the variations in iron ore origin and iron manufacture, wrought iron can be inferior or superior in corrosion resistance, compared to other iron alloys. There are many mechanisms behind its corrosion resistance. Chilton and Evans found that nickel enrichment bands reduce corrosion. They also found that in puddled, forged, and piled iron, the working-over of the metal spread out copper, nickel, and tin impurities that produce electrochemical conditions that slow down corrosion. The slag inclusions have been shown to disperse corrosion to an even film, enabling the iron to resist pitting. Another study has shown that slag inclusions are pathways to corrosion. Other studies show that sulfur in the wrought iron decreases corrosion resistance, while phosphorus increases corrosion resistance. Chloride ions also decrease wrought iron's corrosion resistance.Wrought iron may be welded in the same manner as mild steel, but the presence of oxide or inclusions will give defective results.
The material has a rough surface, so it can hold platings and coatings better. For instance, a galvanic zinc finish applied to wrought iron is approximately 25–40% thicker than the same finish on steel. In Table 1, the chemical composition of wrought iron is compared to that of pig iron and carbon steel. Although it appears that wrought iron and plain carbon steel have similar chemical compositions, that is deceptive. Most of the manganese, sulfur, phosphorus, and silicon are incorporated into the slag fibers in the wrought iron, making wrought iron purer than plain carbon steel.
Amongst its other properties, wrought iron becomes soft at red heat and can be easily forged and forge welded. It can be used to form temporary magnets, but it cannot be magnetized permanently, and is ductile, malleable, and tough.
no relation