A Feeding Strategy in Inner L-Shape Ring Hot Rolling Process

In order to make the inner L-shape ring polling process with a closed die structure (ILRRCDS) on the top and bottom of the driven roll stable, at first, this paper established the mathematical model for ILRRCDS. Then, the plastic penetration and biting-in conditions for ILRRCDS were deduced based on plain ring rolling theory. Moreover, a feeding strategy that can realize a constant growth of the ring’s outer radius was proposed and the reasonable value ranges of the feed rate of the mandrel were determined. The numerical simulation model for ILRRCDS is established based on ABAQUS software. Finally, the equivalent plastic strain (PEEQ) and temperature distributions of rolled ring were obtained. The results indicated that the proposed feeding strategy can realize a stable ILRRCDS. At the end of ILRRCDS, the PEEQ at the inner radius surface of the ring is maximum, the PEEQ at the outer radius surface of the ring takes the second place, and the PEEQ at the middle part of ring is minimum. With the increase of rolling time, the higher temperature zone of the rolled ring gradually moves from the center part of the ring to the “inner corner zone” of the ring.

The Optimal Design for Ring Blank Dimensions in Inner L-Shaped Ring Rolling Process

As the needs of profiled rings continuously increase, studies about profiled ring rolling processes is becoming a hot problem. This paper established a FE model of hot ring rolling process of inner L-shaped ring based on ABAQUS/Explicit software. The reasonable value range of mandrel feed rate is determined at first. Then the deformation characteristics of rings are analyzed and compared in L-shaped ring rolling process under four different ring blank dimensions. Finally, for realizing a steady rolling process and obtaining good dimensions properties of rolled ring, an appropriate ring blank dimension is given.

The Effect of the Initial Temperature of Ring Blank on Conical Ring Rolling Process

A FE model of radial conical ring rolling process with a closed die structure on the top and bottom part of driven roll (RCRRCDS) process was set up based on ABAQUS/Explicit software. The effect of the initial temperature of conical ring blank on equivalent plastic strain (PEEQ) and temperature distribution of rolled ring, average rolling force and average rolling moment was investigated. The results indicated that with the increase of the initial temperature of ring blank, the PEEQ distribution of rolled ring becomes uniform at first and then less uniform; the temperature distribution gradually becomes homogeneous; and both average rolling force and average rolling moment decrease. When the initial temperature of ring blank is 925°C, the PEEQ distribution of rolled ring is most uniform; the temperature distribution of rolled ring is relatively uniform; the average rolling force and average rolling moment are relatively smaller.

Influence of the Intermediate Annealing on Deformation Ability of the Cold Rolled Ring

This paper studies the influence of the intermediate annealing on deformation ability of the cold rolled ring. The results show that: intermediate annealing can improve the ability of plastic deformation of the cold rolled ring, ring rupture occurred after 62.5% thickness reduction, on the other side the ring suffering intermediate annealing still be intact by rolling to upon 64.8% thickness reduction. The mechanism of the intermediate annealing improving deformation ability of cold rolled ring is explored by using optical microscopy, scanning electron microscopy, micro hardness tester and other materials characterization methods. It is found that after intermediate annealing, the amount of carbide particles significantly reduce and the hardness decrease. Meanwhile, dissolution of partial carbides occur during the cold ring rolling process, and with the increasing of the cold rolling deformation, the quantity of the dissolution of cementite in pearlite will increase, which resulting in the improvement of the deformability of the cold rolled ring.

Effects of Rotational Speed of Driver Roll on Hot Ring Rolling of 6061 Aluminum Alloy by 3D FE Simulation

In this paper, a 3D elastic-plastic and coupled thermo-mechanical FE model of radial ring rolling of 6061 aluminum alloy is developed, and the hot rolling process with different the rotational speed of driver roll n is simulated by using the dynamic explicit code ABAQUS/Explicit. The influence laws of the rotational speed of driver roll on the uniformity of strain and temperature distribution (STD), fishtail coefficient, roll force, contact area and roll moment are revealed respectively. One optimum n is obtained, under which SDT is relatively uniform; meanwhile, another optimum n is obtained, under which the quality of end-plane of the rolled ring is the best. The result can provide a valuable guideline to research and optimum of the hot ring rolling of aluminum alloys.