The Study On Microstructure And Properties Of Textile Steel Ring

The steel ring, which is used as one of the key components on ring spinner, realizes twisting and winding of the yarn with high-speed ring traveler. The quality of spinning, spinning efficiency and cost are directly affected by the properties of the steel ring.In this paper, a detailed comparison of Bracker and domestic bearing steel ring was carrried out from the aspects of matrix organization, surface alloy layer and mechanical properties. The results showed, the grain size and martensite of Bracker bearing steel ring was more refined than the domestic one. The chromium layer of Bracker shows a higher density and improved bonding strength. The carbide content in Bracker ring is higher, with a smaller size. Austenite content in matrix organization of Bracker and domestic ring are 0% and 10.62%. Size deformation caused by organization transformation in the process of operation and impact from ring traveler are reduced because of the relatively lower austenite content, thus the service life of ring can be promoted; Due to the higher carbon content in Bracker steel ring, the carbon content of martensite is relatively lower, thus the hardness of martensite is deduced. The definition of the hardness of steel ring should be based on both failure forms and wear type. It is one-sided to improve wear resistance of steel ring only by acquiring a high hardness.The influence of the deep cryogenic treatment process on the microstructure and properties of GCr15 bearing steel ring is also studied. The results show that, with the time of deep cryogenic process increased under-78℃, the content of austenite in GCrl5 steel ring gradually reduced, transformation of austenite is fast at beginning and slower later. At the same time, the surface hardness of steel ring is increased, however with lower amplitude. This phenomenon was mainly due to the increase of the residual austenite transformation in the steel ring, when the time of the deep cryogenic treatment was increased. A large number of martensite improved the hardness of steel ring. Meanwhile, in the process of martensitic transformation, the volume of material was expanded, causing pressure on the surrounding austenite and blocked the retained austenite from transforming to martensite. The increase speed of hardness was slow down while the rate of transformation of austenitic to martensite turned to be decreased. Austenite content of the studied GCrl5 steel ring without deep cryogenic treatment was 11.3%, the hardness was 696.7 HV. Austenite content of-78℃and 196℃deep cryogenic treatment 2h of GCr15 steel ring were 5.5% and 1.5%, and the hardness were 654.4HV and 749.1HV. Along with the decrease of cryogenic temperature, the austenite content decreased, the hardness increased firstly and then dropped down.The wear test indicated, the wear resistance of GCrl5 bearing steel was significantly improved by deep cryogenic treatment. The wear amount was 7mg without the cryogenic treatment. After deep cryogenic treatment under-78℃and 196℃, the wear amount were 4mg and 2mg. Along with the decrease of cryogenic temperature, the wear resistance of GCr15 bearing steel ring gradual increased. Deep cryogenic treatment improved the wear resistance of GCr15 bearing steel.