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Wootz steel is a steel characterized by a pattern of bands or sheets of micro carbides within a tempered martensite or pearlite matrix. It was developed in India around 300 BC. The word wootz may have been a mistranscription of wook, an anglicised version of urukke, the word for melting in Tamil and Malayalam or urukku(உருக்கு) (ഉരുക്കുകൊണ്ടുണ്ടാക്കിയ), the word for steel in Kannada, Telugu and many other southern Indian languages.
According to traditional history wootz steel originated in India before the beginning of the common era. There is archaeological evidence of the manufacturing process in South India from that time. Wootz steel was widely exported and traded throughout ancient Europe and the Arab world, and became particularly famous in the Middle East, where it was known as Damascus steel and was later traced to workshops in western India.
In ancient times, thirty pounds of steel was a precious gift, deemed by King Porus worthy of presentation to Alexander the Great. Another sign that Ancient India was celebrated for its steel is seen in a Persian phrase - to give an "Indian answer," meaning "a cut with an Indian sword."
Legends of wootz steel and Damascus swords aroused the curiosity of the European scientific community from the 17th to the 19th Century. The use of high carbon alloys was not known in Europe previously and thus the research into wootz steel played an important role in the development of modern English, French and Russian metallurgy.
In 1790, samples of wootz steel were received by Sir Joseph Banks, President of the British Royal society. These samples were subjected to scientific examination and analysis by several experts.
Specimens of daggers, and other warlike weapons were sent by the Rajahs of India to the International Exhibition of 1851 and 1862. Though the arms of the swords were beautifully decorated and jeweled, they were most highly prized for the quality of their steel. The swords of the Sikhs were said to bear bending and crumpling, and yet be fine and sharp.
A critical characteristic of wootz steel is the abundance of ultrahard metallic carbides in the steel matrix precipitating out in bands, making wootz steel display a characteristic banding on its surface. Wootz swords, especially Damascus blades, were renowned for their sharpness and toughness. Peter Paufler from Dresden University of Technology has discovered evidence of carbon nanotubes in wootz steel, although this is disputed.
The techniques for its making died out around 1700. Oral tradition in India maintains that a small piece of either white or black hematite (or old wootz) had to be included in each melt, and that a minimum of these elements must be present in the steel for the proper segregation of the micro carbides to take place.
Russian metallurgist Pavel Petrovich Anosov (see Bulat steel), Dr. Oleg Sherby and Dr. Jeff Wadsworth and Lawrence Livermore National Laboratory have all done research, attempting to create steels with similar characteristics to Wootz. However none have had any success so far and the original techniques used to produce wootz steel in India have been lost for centuries.
There are no patents or trademarks for wootz steel (US Patent and Trademark Office).