A new method (thermal spokes) is proposed to simulate the guide rolls in FE analysis of the Ring rolling process. So far this method is the only one, capable of calculating guide rolls reaction contact forces related to the stiffness of their, adjustment mechanism. The method is simple to use, does not introduce further nonlinearities and could be used in any kind of FE formulations. The method is successfully employed in FE analysis of rectangular and T-section Rings. The results of the thermal spokes method, a new analytical method based on lever arm principle with experimental results are in good agreements. This analysis shows that the guide rolls greatly affect the process.

The main purpose of this article is calculating forces and moments of each of the process rolls for designing and manufactuRing of Ring rolling machine to be used for airplane engine cases. Axial redial Ring rolling process was simulated by finite element method. To validate the results, output of simulation of rolling a simple Ring made of Ti-6Al-4V alloy was compared to experimental results. CompaRing results show good accuracy of simulation. Also in this article, a new method for simulating of guide rolls proposed, that is more simple and efficient than the previous methods.

Work rolls in the hot Ring rolling process are susceptible to various damages due to the contact with hot metal. Thermo-mechanical fatigue is one of these damages. In order to predict failure resulting from the thermo-mechanical stress in the work rolls, the developed code in ABAQUS was used. A comparison between three-and two-dimensional models was made and also, thermal and thermo-mechanical responses of work rolls with variable boundary conditions were investigated. The results demonstrated that by applying mechanical and thermal loads separately or simultaneously, the response of work rolls is completely different. In the mandrel, the location of the maximum equivalent stress is on the surface, while the location of equivalent maximum stress is on the subsurface of the main roll. Upon utilizing cumulative damage rules and the stress-life method, the thermo-mechanical fatigue life was estimated. The cumulated damage to the surface of the mandrel was higher than that to subsurface regions. In contrast to the mandrel, the cumulated damage to the subsurface of the main roll was higher than that to the surface regions. In hot Ring rolling machines, these locations are prone to crack initiation as a result of the thermo-mechanical fatigue of the work rolls.

In recent years, Ring rolling process is used to produce seamless rims in many industries, including the aviation and railway industries. The reason for this is the advantages of this process, such as saving money and materials, high quality and high efficiency. In this research, the shaping of the front and rear spools of an airplane engine compressor has been investigated using the Ring rolling process. Due to the complexity of the internal and external surface shapes of these spools, it is difficult to simulate the Ring rolling process for them. For the performed simulation, the stress applied to the main roller has been checked with the assumption of the shape of the rollers. Also, the forces acting on the main roller in the case where the rollers are assumed to be malleable have been extracted and compared with the previous results where all the rollers are rigid. In both spools, there are complex forms designed on the surface of the roller. If the concentration of stress created at the sharp points duRing elementing is ignored, the stresses created on other parts of the mold are around 400 MPa. Therefore, H13 steel can be used for the front and back spools to make all molds. But it is suggested that the surface of the shell should be as hard as possible and after making molds and using them for the mass production of shells, these surfaces should be constantly reviewed.

Hot Ring rolling is a highly nonlinear, unsteady-state and asymmetry process which is affected by many parameters. The friction coefficient between the Ring, the driver roll and the idle roll is one of the problems, which has significant effect on the quality of final product. In this study, the effect of these two parameters on hot Ring rolling was investigated based on a 3D coupled-thermo mechanical FE model. The 3D model of Ring rolling process was built in ABAQUS including Ring, driver roll, idle roll and guide roll. The value of fishtail defect was measured for different friction coefficients between Ring and driver roll and also Ring and idle roll. The results show that the value of the fishtail defect decreases with the increase of the friction coefficient between the Ring and the idle roll or the decrease of friction coefficient between the Ring and the driver roll. Furthermore the value of the fishtail defect increases with the decrease of the friction coefficient between the Ring and the idle roll or the increase of friction coefficient between the Ring and the driver roll. Also the value of these two parameters must be restricted in a specific range, upper and lower values are not allowed. The obtained results may provide a guide for process optimization.

Ring rolling process is used in the production of seamless Rings. The most important advantages of these Rings are favorable grain flow and crack growth resistance. Aircraft engine spools are usually produced by means of this process. Failure of the work rolls duRing forming of spools leads to unacceptable microstructure, geometrical structural and irreparable damages. Evaluation of the work rolls conditions of the Ring rolling machine has a direct effect on the geometrical and mechanical properties of the output Ring. By making use of Abaqus simulation, the loading history was extracted and applied to the work rolls. According to the loading history, stress-life method and cumulative damage relations were performed. The main-roll is significantly affected by mechanical stresses. On the other hand, the mandrel is affected by thermal stresses. In general, the proper cooling has a significant effect on the service life of the mandrel. In addition, the effect of bending stresses on the mandrel’ s life is not significant. The results of the research show that the responses of the work rolls to thermo-mechanical loads are completely different. The probability of damage and crack initiation due to thermo-mechanical loads in the main-roll and mandrel are below and on the work rolls surface, respectively.

rolling Ring is one of the most important metal forming processes for fabricating rounded geometries with optimal mechanical properties in the environmental direction. The ability to fabrication of two-layer Rings can be used in many industries. One of the properties of these Rings is the lightweight with high strength or wear resistance along with high strength. In this research, we have tried to study the Ring rolling process of the bonded two-layer Ring and its effective parameters duRing the process using finite element analysis by ABAQUS software and experimental test. The Rings are attached for process simulation and empirical testing. In the end, a Ring of two-layer of pure Lead 99. 99% and Tin 63% was formed. Based on the results obtained from this analysis and according to the dimensions and parameters considered for performing the process, the tension created in the bonded two-layer Ring is between the values of 1. 146×105-1. 800×107Pa and it has a strain of 0-1. 187. Its contours of strain and stress are represented to better understand the process. ConsideRing the results obtained from the simulation of the process, an experimental study of the Ring rolling process of the bonded twolayer Ring was conducted. The method of this study was first designed by the modeling software to design the casting model and then by designing the test, the number of tests required for the experimental test was obtained and then the number of materials needed for the test was calculated. After testing, the mechanical and metallurgical properties of rolled double rolled Rings were investigated.

Hot rolling of a large Ring of titanium alloy (LRT) is a highly nonlinear incremental forming process with coupled mechanical and thermal behaviors (MTBs) which significantly affect microstructure and properties of the Ring. The feed rate of idle roll and the rotational speed of driver roll have major effects on ovality of the Ring. In this paper, the effects of these parameters on the ovality of the Ring have been investigated by a coupled thermo-mechanical 3D-FEA. The results show that the ovality of Ring blank decreases with the increase of the rotational speed of driver roll or the decrease of the feed rate of idle roll. The results obtained can provide a guide for forming parameters optimization.