Key point–Water cooling for steel bars
Each piece of metal need to be hardened during manufacturing, so hardening is also an important procedure during steel bar hardening and tempering process. If the hardening is not good, the steel bar after hardening and tempering will have deformation. Here Forever will take the example of steel bar induction hardening and tempering equipment to explain the water cooling process.
IF water quenching equipment mainly includes three elements: water intensity (water pressure, flow), water spray time and cooling temperature control. Here we are using numerical simulation method to do quenching process analysis for 300MW generator rotor.
Water spray strength is the reaction of water flow density and pressure, the specific performance is the number of changes in heat transfer. We set thermal coefficient in the spray cooling process does not change with time and study the import of water strength through chaning the the thermal coefficient. Long time means surface cooling is slow, short time means cooling fast. Spray water intensity changes have a great impact on the surface cooling rate. With the increase of depth, the influence of the change of water intensity on the cooling rate is weakened.
2.Spray water time
The selection of water spray time depends on the required heart temperature. The temperature must be cooled below a certain temperature in order to make the material achieve good overall mechanical properties, but too low temperatur will increase the risk of quenching. Generally, the cooling temperature is controlled within the range of 200-300 ° C, and the control temperature increases as the sectional size increases. .
3. Spray water stop-temperature control
During the process of water spraying on the steel bar, the water will take the heat of the bar surface to reduce the surface temperature. Then the inside temperature will transfer to the surface. Once the water spraying stop, the inside temperature will continue to transfer to the surface. As the surface heat exchange ability reduce, the heat transferred from inside can not be taken with cooling medium. So the surface temperature will recover and reach the new temperature balance state.
More details, welcome to contact Forever-Professional manufacturer of steel bar heating furnace in China.
Overseas manager: Tom Wang
Phone: 0086-13303078975(whatsapp, wechat,line)
Specialist of induction heating system in China; Glad to be your business partner in induction heating field.
Post time: 01-11-2018