The Ring Rolling Process

ทฤษฎี:

Ring rolling has advanced but versatile rolling process as it can be performed on the material at high temperatures and also at ambient temperatures.
The main applications of the process are for the production of railway tyres, anti-friction bearing races, and a range of ring shaped components used in the automotive and aerospace industries.

Rolling is continuous forming of metal between a set of rotating rolls whose shape or height is incrementally reduced to produce desired section through imposing high pressures for plastic deformation. It is the process of reducing thickness, increasing length without increasing the width markedly. The ring rolling process can be performed with the material at high temperature (hot) or initially at ambient temperature (cold). Ring rolling is an advanced technique to manufacture seamless rings with flexible cross-sectional shape, improved grain structure, and minimal scrap.

The process and equipment are similar in principle to rolling mills used for plate production. Indeed in both processes the metal is rolled between two rolls which move toward each other to form a continuously reducing gap. In ring rolling, the rolls are of different diameters and geometries.

The ring rolling process is basically used in the production of railway tyres, anti-friction bearing races and different ring shaped work pieces for automotive and aerospace applications. The advantages of the ring rolling process include short production time, uniform quality, close tolerances and considerable saving in material cost.

Moreover the main advantage of the work pieces produced by ring rolling process, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In figure 1 the main production steps of the ring rolling process are summarized.



Figure 1: Main characteristic of ring rolling

As shown in figure 1, it begins with a forged bar that has been upset (a) and pierced (b) to obtain a hollow circular preform. The preform is placed over the idle roll that is forced toward the driven roll (c). At the same time, the axial rolls apply pressure in a direction parallel to the ring axis. So the idle roll reduces the width while the axial rolls reduce the height of the ring cross section.

The coupled idle and axial rolls movement imparts the desired shape to the cross section and increase the ring diameter. The work piece starting section could have a rectangular or complex shape. As can be observed from figure 1, due to the nature of the process different rolling mills (driven roll, idle and axial roll) are involved and the correct selection of the process parameters is not so feasible.

Also, the ring rolling process is widely used to produce seamless rings by forming by a continuous but gradual process with various outer ring diameters for power generation plants, aircraft engines and large cylindrical vessels. Advantages of the ring rolling process compared to the ring forging process are the fast working time with the grain flow being formed continuously which is favorable by nature.

ค้นหาฐานความรู้

ใส่ข้อความเพื่อค้นหา:

ค้นหาโดย

เต็มคำ
คำสำคัญ

หัวเรื่อง
บทคัดย่อ

The Total Materia database contains many thousands of forging materials across a large range of countries and standards.

Where available, full property information can be viewed for materials including chemical composition, mechanical properties, physical properties, advanced property data and much more.

Using the Advanced Search page, it is possible to search for materials by their key descriptive words detailed in the standard title by using the Standard Description function of Advanced Search.

It maybe that you need to further narrow the search criteria by using the other fields in the Advanced Search page e.g. Country/Standard.

Then click Submit.

solution img

A list of materials will then be generated for you to choose from.

solution img

After clicking a material from the resulting list, a list of subgroups derived from standard specifications appears.

From here it is possible to view specific property data for the selected material and also to view similar and equivalent materials in our powerful cross reference tables.

solution img

For example, by clicking on the mechanical properties link on the subgroup page it is possible to view mechanical properties data for the material including yield stress, tensile stress, elongation and impact data.

solution img

For you’re a chance to take a test drive of the Total Materia database, we invite you to join a community of over 150,000 registered users through the Total Materia Free Demo.