You will need
- - oil bath with oil AC-8;
- - electricity
To restore the elasticity of the springs by means of thermomechanical way to install the spring in a vise and squeeze the spring so that its turns touch each other. Then skip through spring electrical current from 200 to 400 amps for 20-30 seconds. The amperage and the exposure time of pick up experimentally depending on the size of the recoverable part or in a scientific way, calculating the values of the parameters needed for heating the spring up to 800-850 degrees. Visually, this temperature is determined by the fact that when it reaches the metal red with heat.
After heating to the desired temperature, turn off the power supply and start to loosen the grip so that the spring began to slowly stretch. After the item is stretched to its extreme length, secure the end of the end of the spring on the jaws in any way and stretch the spring at 20-30% of its standard length. The whole process of stretching should last at least 30 seconds. At the end of the swipe-hardened spring – put it in an oil bath. In this case it is best to use the oil type as-8.
To restore the spring by an electrochemical method use a lathe. Install mandrel in the Chuck of the lathe. It will secure the spring using the clamp. In the tool holder of the machine install the mandrel with deforming roller from heat-treated steel SHKH15, the hardness of 60-62 HRC. On the rails of the machine bed attach rack with sliding rollers and rigidly connect it to the caliper with the lathe. Retighten the mandrel with pre-installed it spring back centre set in the tailstock quill.