HEAT TREATMENTS ON TITANIUM AND ZIRCONIUM
In THE piping SECTOR, titanium and zirconium are used when the problems connected to corrosion resistance of (TO) the transported fluids become unsolvable, even using austenitic steels or nickel alloys.
Stress-relieving heat treatment of titanium and its alloys
The stress-relieving heat treatment enhances the maintenance of the geometrical and dimensional stability of the assembled component, reducing the effects of residual stresses due to the work machining, plastic deformation, welding and heat treatments with metallurgical changes.
The high reactivity of titanium above all (NON CAPISCO IL SENSO) at high temperatures makes it compulsory to have the component completely cleaned, degreased and dried before the heat treatments. The nonobservance of this specific care can induce to the contamination of the material with consequent risk of embrittlement or tendency to stress-corrosion cracking.
The reduction of the stresses is substantially connected to the temperature at which the treatment is executed. Every KIND/TYPE OF titanium has its own stress-relieving temperature to avoid the beta transformation.
For all this high value components, which undergo serious testings with treatments monitored by third institutions, it is important that our customers can count on a structured and trustworthy supplier as TRATER, which is provided with personnel and means to execute at best thermal cycles and always deliver items always correctly treated.
Oxidation heat treatment of zirconium
Zirconium, even IF not treated, has optimal (EXCELLENT) abilities of corrosion resistance, thanks to the very stable oxide that covers the surface, whose creation and thickening can be accelerated into the oven at a specific temperature.
The complexity of this (work) process consists in the (IS CAUSED BY THE HIGH REACTION OF ZIRCONIUM TO IRON AT SOAKING TEMPERATURE) fact that, at soaking temperature, zirconium is very reactive to iron, therefore a polluting particle, depositing on the surface OF THE ITEM, damages the material which has a very relevant cost. These treatments have to be executed in deferrizated (IRON FREE) ovens, with oxidizing atmosphere and with filtration systems of combustion air, in order to remove every ferrous particle in the air.
Before treatment, zirconium has to be cleaned and handled in deferrizated (IRON FREE) environments, and moved with dedicated equipment and clothes to avoid every contamination.
During treatment, particular precautions must be adopted to the supports (?) to avoid the iron pollution of the material (IN ORDER FOR THE MATERIAL NOT TO BE POLLUTED WITH IRON).
After the oxidation, the material is inert to every kind of corrosive agent. If the material does not reach the exact oxidation temperature or does not maintain it for the prescribed minimum time, the components will rapidly wear out once in exercise, creating frequent stop to the chemical plants where they are installed or potentially very expensive malfunction.
Trater has acquired a remarkable experience on the treatment of zirconium and proposes itself as a reference to solve all the treatment problems on items in this material.