Heat Treatment

Metallurgy - Heat Treatment

Many metals are only rendered useful through heat treatment. The spectrum of product characteristics obtained in this way includes hard, ductile, soft and differently colored surfaces. As glowing metals react readily with air, protecting gases in the furnace atmosphere are indispensable. In many cases, nitrogen is used as the inert medium. Competence through gas technology If a particular metallurgical effect is to be achieved with the gas, however, reactive gases must be added. The addition of small quantities of propane to the nitrogen, for example, has proved particularly effective. This is regulated with the help of an integrated sensor system so that only the amount of propane needed is used. This optimized technology of using propane in nitrogen or hydrogen and hydrogen mixtures is protected by a number of patents, again emphasizing the competence of Messer in this field. Hydrogen - reactive and effective Hydrogen is mainly used for the annealing of high alloy steels. Here, not only is its reductive capacity utilized, but also its cleansing effect on surfaces. Its high thermal conductivity and thermal capacity also appreciably improve the economic efficiency of high convection annealing in bell furnaces. Advantages through innovation In the Endolin® process, a special shielding gas atmosphere of endogas/nitrogen mixtures is used for the heat treatment of steel and NF alloys in industrial furnaces. Endolin® gas mixtures are an economical alternative wherever a supply of pure hydrogen is too costly and selfgenerated exogas or monogas no longer meets the stricter quality requirements for the finished products. As opposed to exogas, the carbon level in the furnace gas can only be set and regulated with diluted endogas. A major advantage, however, is that endogas and nitrogen can be introduced separately in different regions of the furnace. In addition to the recrystallization annealing of steel, Endolin® can be used in sintering,...