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When was martensite first found/discvered?
This is a very interesting question. Iron has been known of and worked for approximatly 4000 years. However its useage only became recognized around 12OOBC. The reason being, was that it was extremely difficult to smelt, melt, cast or forge, simply beacuse of temperature. However, the ancient Chinese made use of a dual air blower box to elevate the iron's temperature. The source of the thermal energy was a fire made of wood and charcoal. They did not realize the fact that while the iron was being heated in the fire, it was also absorbing carbon for the wood and charcoal fire. Thus it was transforming from iron into what we know today as steel. (Steel is simply an alloy of iron plus carbon) In the country of India, the Indian blacksmiths (3500 years ago) developed a material which they called 'Woodtz' iron. (This was simply iron plus carbon)steel). This steel was used to make agricultural implements, and weapons. Steel then began to take over form the use of bronze because it could be made harder, and stronger than its bronze counter part. There is excavated evidence of articles from the ancients, that have been microscopically examined and it has been seen that martensite was present, especially in the near surface area's of the artifact. Martensite was so named after Adolph Martens who was a german engineer who made some exciting observations with a microscope at around 400 magnification. There were many other metallurgical engineers who made significant contributions to the observation of martensite and how it is formed. There are many contributions that were made by the other metallurgical engineers, and they should be recognized. However, the phase of martensite was named after Adolph Martens.

Bodycote nitriding aquistion
Well, it would seem that Bodycote is adopting a philosopy of 'if you cannot beat them, buy them'!! The Bodycote latest aquistion of one of the Nitrex operations in Poland certainly begins to strengthen Bodycote as one of the very serious leaders in the process of nitriding technology.With the earlier aquisition that Bodycote made with the French company, they re certainly almost 'out in front' (so to speak)\I am sure that it will be a worthy aquisition for Bodycote.

We have an endothermic gas generator, our question is how frequently should it be burned out?
This will depend on what carbon potential you are running the generator at. Generally its carbon potential is approximatly 0.35% carbon. However, this can change with variations in the natural gas composition, and of course the air mix. It is generally better to control the generator with a three gas analyzer and to monitor the Carbon Monoxide, Carbon Dioxide and methane. You could go to a four gas analyzer and add nitrogen as a control gas along with the previously mentioned gases. The frequency of burn out should be (manufacturers recommendations) at once per week. However, it could be stretched out to once every two weeks. But do not let it slip beyond that.The burnout temperature is generally at approximatly 1500F(815C)

When we admit endothermic gas into our continuous furnace and we are heat treating AISI 1050 steel we produce a decarburized surface on the steel, yet it appears to be clean after quenching. What is causing the decarburization?
The endothermic gas is causing the decarburization. You need to enrich the endo gas at the furnace with a hydrocarbon gas such as methane. The endo gas will have a carbon potential of approximatly 0.35% carbon. Therefore you do not have equilibrium in the atmosphere to the carbon content of your steel. Thus, the result is decarburization.

What is meant by the term 'hardenability'?
The term 'hardenability' is a term that is used to described a steels ability to harden. It does not mean 'what hardness can be achieved.' Hardenability is usually determined by the Jominy End quench test. The method involves maching a pice of steel to specific dimensions, heating the steel to its appropriate austenitizing temperature, followed by spraying a volume of water onto the end face of the bar. The effect will be for the face to cool rapidly and then to cool slower and at a progresive rate along the length of the bar. The bar is marked off at 1/16th inch internvals. After the test is complete, then the bar is hardness tested every 1/16 inch and a curve is plotted. This is the steels ability to respond to a specific heat treat procedure in terms of hardness values across its cross section. In other words it will show the depth of hardening across an equivelent diameter bar of steel. The addition of alloying elements will affect the steels'hardenability'