How to Reduce the Consumption of THI®F-502 PAG Quenching Fluid

(1) Unit Consumption of THI®F-502 Quenching Fluid

To study the loss quota of quenching media on the surface of quenched workpieces, we consulted extensive international and domestic literature and sought advice from senior experts at leading research institutes. The consensus is that our methodology is scientifically sound, and the data are reliable and credible. In addition, by reviewing the historical consumption data of more than a dozen users, we confirmed that the results are consistent with real-world conditions.

Experimental conclusions are as follows:

Using mechanical oil for quenching: unit consumption 114.69 g/m², equivalent to 0.90 CNY/m²

Using THI®F-502 PAG quenchant (5.9% concentration): unit consumption 25.41 g/m², equivalent to 0.50 CNY/m²

Using THI®F-502 PAG quenchant (10% concentration): unit consumption 33.61 g/m², equivalent to 0.67 CNY/m²

Based on the above data, PAG quenchants offer significantly lower consumption compared with oil, making them more economical, safer, and more environmentally friendly.

(2) How to Reduce Drag-Out

A key characteristic of THI®F-502 PAG quenching fluid is its inverse solubility at 74°C. When the discharge temperature becomes too high, the PAG polyether component precipitates out of the water and adheres to the surface of the workpiece, as shown in the figure below.

When workpieces at 800–900°C are transferred from the furnace into the quenching tank, the discharge temperature may exceed 100°C. This is higher than the inverse solubility temperature of PAG. At this point, the PAG polymer has not yet redissolved into the quenching solution, so a higher discharge temperature results in a greater amount of drag-out.

The discharge temperature can be appropriately reduced, and the workpiece’s residence time in the quenching fluid can be extended to allow the polymer adhered to the workpiece surface to fully dissolve. This significantly reduces drag-out losses. However, for workpieces with high hardenability, it is essential to ensure that the discharge temperature is not too low to avoid cracking. The discharge temperature must be adjusted based on the actual heat-treatment conditions on site.

Some of our customers, in order to reduce operating costs, rinse the workpieces with tap water after quenching. They then use the rinsing water as make-up water for the quenching tank, allowing the precipitated PAG to dissolve and return to the system. This approach is more suitable for small components. However, some customers prefer not to add an extra process step, as the workpieces may be prone to rust. Your company may select the most appropriate method based on actual production needs.

Tags:Reduce Quenchant Consumption, Lower Operating Cost, PAG Quenchant Saving, Quenchant Maintenance, THI F-502, Honorhonest, Heat Treatment Efficiency, Cost Control