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The effects of forming parameters on conical ring rolling process.

Meng W, Zhao G, Guan Y - ScientificWorldJournal (2014)

Bottom Line: The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied.The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces.Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan, Shandong 250061, China.

ABSTRACT
The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

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Related in: MedlinePlus

(a) Conical ring blank and rolled conical ring; (b) the PEEQ distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s; (c) the temperature distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s.
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fig6: (a) Conical ring blank and rolled conical ring; (b) the PEEQ distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s; (c) the temperature distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s.

Mentions: Figure 6(a) shows the conical ring blank and the rolled conical ring. Since the PEEQ and temperature distributions of the conical ring are axis-symmetric about its center, a certain cross-section of rolled conical ring “S-S” is selected to investigate the PEEQ and temperature distributions at t = 33.9 s, as shown in Figures 6(b) and 6(c). In Figure 6(b), the PEEQ at IL and OL are bigger than that at the middle layer (ML). The reason can be explained as follows. On the one hand, since the conical ring suffers from the rolling forces of driven roll and mandrel along radial direction and the tangential stress along the circumferential direction, there are a contracted metal flow tendency along the radial direction and expanded tendency along the axial and circumferential directions. On the other hand, since the conical ring suffers from the restrictions of the top and bottom part of the driven roll, the metal flow tendency along the axial direction is restricted. In this situation, the ring radius continuously increases, the thickness of ring wall gradually decreases, and the height of the ring is invariable. The large deformation mainly concentrates on IL and OL of the rolled ring. It also can be seen that the PEEQ at l layer-height of IL is larger than that of OL. The reason is that φ(l, t) < 0 according to the conditions of Case 1 and ((11)). This means that the feed amount of the driven roll at l layer-height is smaller than that of the mandrel and the larger deformation locates at IL of the rolled ring.


The effects of forming parameters on conical ring rolling process.

Meng W, Zhao G, Guan Y - ScientificWorldJournal (2014)

(a) Conical ring blank and rolled conical ring; (b) the PEEQ distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s; (c) the temperature distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4150487&req=5

fig6: (a) Conical ring blank and rolled conical ring; (b) the PEEQ distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s; (c) the temperature distribution at the cross-section “S-S” of rolled conical ring at t = 33.9 s.
Mentions: Figure 6(a) shows the conical ring blank and the rolled conical ring. Since the PEEQ and temperature distributions of the conical ring are axis-symmetric about its center, a certain cross-section of rolled conical ring “S-S” is selected to investigate the PEEQ and temperature distributions at t = 33.9 s, as shown in Figures 6(b) and 6(c). In Figure 6(b), the PEEQ at IL and OL are bigger than that at the middle layer (ML). The reason can be explained as follows. On the one hand, since the conical ring suffers from the rolling forces of driven roll and mandrel along radial direction and the tangential stress along the circumferential direction, there are a contracted metal flow tendency along the radial direction and expanded tendency along the axial and circumferential directions. On the other hand, since the conical ring suffers from the restrictions of the top and bottom part of the driven roll, the metal flow tendency along the axial direction is restricted. In this situation, the ring radius continuously increases, the thickness of ring wall gradually decreases, and the height of the ring is invariable. The large deformation mainly concentrates on IL and OL of the rolled ring. It also can be seen that the PEEQ at l layer-height of IL is larger than that of OL. The reason is that φ(l, t) < 0 according to the conditions of Case 1 and ((11)). This means that the feed amount of the driven roll at l layer-height is smaller than that of the mandrel and the larger deformation locates at IL of the rolled ring.

Bottom Line: The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied.The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces.Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan, Shandong 250061, China.

ABSTRACT
The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

Show MeSH
Related in: MedlinePlus