Study On Clean Water-based Quenching/tempering Medium For Textile Steel Ring Travelers

Heat treatment is most important in mechanical industry, but it is easy to cause environment pollution. Currently, the most common used quenching and tempering medium for steel ring travelers is oil. However, oil is expensive, easy to start fire and cause heavy pollution. Especially, it is time consuming to remove the oil stain on work pieces, which severely affect the product efficiency. Besides, the waste oil is not easy to recover. Therefore, there is an urgent need to look for clean medium to replace oil. The investigation into clean quenching and tempering medium is carried out based on clean heat treatment technology for steel ring travelers.The results show that:(1) in the heat treatment process, the heating temperature and holding time are vital factors to obtain uniform microstructure and good performance. The optimal heat treatment process is obtained by orthogonal experiments. (2) Based on experiments, it is found that 0.25% PVA solution can suit the quenching of 80steel. The cooling velocity can be adjusted by different concentration. But it is difficult to determine the concentration in practice and PVA easily attaches to the work piece's surface, which will increase a lot of difficulties in practical operation. (3) 3%~7% PAG solution could attain the quenching requirement of steel ring traveler. The hardness decreases with the concentration increase. The best effect can obtain with the concentration of 5%~5.75%PAG through many repeat experiments. (4) The new sodium metasilicate solution with 8%~13% could attain the demand requirement. Its cool performance could be adjusted by different concentration which can be easily tested in practice. Besides, it has good antirust performance and its raw material is much cheaper. (5) The alkaline bath with the good temperature uniformity can satisfy the required hardness after temper as well as oil bath. Further more, the ratio of the main compositions of the alkaline bath is very important for its tempering effect. The results strongly indicate that the contents of alkali and the anti-oxidation reagent can significantly affect the hardness. Its optimal composition is derived based on orthogonal experiments and data analysis.The quenching process of steel ring traveler is simulated with ANSYS. The temperature distribution and stress distribution during every period and deferent nodes'cool curves are derived. The working mechanism of cooling is also discussed and the results and analysis reveal some insight into the computer simulation applied on the clean heat treatment.