Solution Anneal & Annealing
Annealing makes metals more formable. When metal is stronger and more ductile, it gives manufacturers more leeway in the fabrication process. There is less risk of
material fracturing from bending or pressing. Annealing can also improve a metal’s ability to be machined and improve the lifespans of the product.
What are the applications and benefits?
The primary applications of Solution Annealing are to improve ductility (e.g. reducing the effects of cold work) and optimise corrosion resistance (e.g. after welding). Solution anneal will get rid of unwanted phases/carbides, redistribute elements and soften a material. It is usually applied to non-ferrous material and exotic material, like stainless steel, nickel based alloys etc.
How does the process work?
The Solution Annealing temperature is dependent on the material. High process temperatures are usually applied to stainless steels and exotic material ranges at temperatures from 1000°C plus. Nonferrous materials are much lower at 500°C plus. Con Mech Engineers has the facility to achieve high temperatures very quickly, or to apply programmed ramp rates should the component require it.
Importantly we load onto Ni /Cr furnace trays (RA330) to provide good support at high temperatures, eliminating the risk of cross contamination from carbon steel. The design of the tray allows free movement of heat during the heating cycle and quenchant during the quench cycle.
Dependent on the grade, section and final mechanical requirements of the material we utilise one of a number of cooling techniques including air cool, rapid air cool, polymer quench and water quench. For air cool we have dedicated still cooling tables inside the building free from draughts to allow all round consistent air-cooling to produce evenly distributed properties throughout the steel. Rapid air blast can deliver a more accelerated cool. Large cooling fans above and below the load can increase cooling rates to achieve properties greater than that of standard air-cooling while protecting against distortion. 316 Stainless steel is water quenched when solution annealing to avoid an unwanted phase called sigma, but if the material is under 8mm a rapid blast can be used to control distortion. 17/4PH material is a age hardening material it is solution annealed to redistribute certain elements back to the grain boundaries ready to precipitate them elements into the grains when age hardening. This material is usually air cooled but sometimes it is rapid air blasted
All stainless grades of steel are stored in a special Stainless Steel Area free from carbon steel contamination. Due to the high value of stainless steel this area is under constant CCTV surveillance.
Which materials can be treated?
Solution Annealing can be applied to stainless steel, duplex, super duplex and bronze alloys. Certain tool steels can be air cooled to harden them up, especially ones with high cobalt content. Rapid air blast may be required if the section size is vast.
How can Con Mech Engineers help?
We can work to your specification or our metallurgist and process development team can custom design a solution annealing process to meet your requirements.