What’s the effect of roller burnishing process on workpiece performance?

What’s the effect of rolling process of workpiece performance?

Surface quality of roller burnishing tool‘s rolling process has the following effects on workpiece performance:

①The effect on wear resistance

The surface roughness has a great influence on the initial wear of friction pairs. But not the less roughness, the more wear-resistant. Under certain working conditions, there is an optimal parameter value of the surface of friction pair , which is about 0.32 ~ 1.25 m.

②Effects of fatigue strength

Under the action of alternating to load, the surface roughness and defect from workpiece are easy to cause stress concentration and fatigue crack damage. For some important parts that bear alternating loads, such as the junction of crankshaft crank and shaft neck, roller burnishing should be carried out to reduce the surface roughness and improve the fatigue strength.

③Effects of corrosion resistance

The rougher the surface of the workpiece, the easier it is to accumulate corrosive substances. The deeper the valley, the effects of the infiltration and corrosion are the stronger. Therefore, to reduce the surface roughness of the parts, it can improve the corrosion properties of the parts.

④Effects of parts’ quality

The rough surface of parts will increase the gap of parts after wear and tear, change the nature of parts, reduce the precision and rigidity of parts, and affect the stability and reliability of operation. Therefore, the surface roughness parameter value of the workpiece with the required parts must be limited.

How to select and use roller burnishing tool?

Selection and use of roller burnishing tool

Usage: the standard type of the roller tool includes the clamping part of morse taper shank and straight shank.

The rolling process is different from the cutting process, which does not require large torque. It can also be used in small power machine tools. The roller burnishing tool can be installed on drilling machine, lathe, hexagon lathe, boring machine, drilling machine and other equipment for processing without special equipment.

Ball burnishing pressure:

When the ball is rolled, the ball can rotate freely, that is, in the direction of main motion and feed direction, it can roll without sliding. Therefore, the surface quality of processed parts is good. The ball rolling pressure can usually obtain a very low surface roughness (Ra0.2μm～0.10μm). Under the condition that the other process parameters are matched, the surface quality of the rolled part can also reach Ra0.05. At the same time, due to the ball and the surface of the workpiece interface is relatively small, therefore, under the condition of the same unit pressure can decrease the total pressure, especially suitable for the outer surface of the small slender precision parts and thin wall parts of inner hole roller.

The ball burnishing tool is simple in structure and light in weight. When the ball is worn, the low price standard ball can be adopted to reduce the cost to a certain extent.

The disadvantage is that the service life of ball burnishing tool is too low, and the ball usually needs to be replaced after 10h ~ 12h continuous use.

Shaft burnishing pressure:

Like a ball burnishing, shaft burnishing not only get a better surface roughness, and overcomes the drawback low life of ball burnishing, also can be used in a large feed, rolling usually use 0.75mm/r-0.80mm/r, so the production efficiency is high.

Turning tool rolling pressure:

The structure is basically the same as that of the tool with replaceable alloy blade, and the operation is the same as that of the tool. Diamond tool head is used in turning tool rolling, which is suitable for high hardness.

In using the roller burnishing tool, we know that it is very important to know the selection, adjustment and model of the roller burnishing tool. The rotation of the roll head and the driving force of the product are all necessary to improve the smoothness of the product. Of course, in addition to these, the conditions of the roller burnishing tool are particularly important, such as the adjustment range of theroller burnishing tool, the size of the workpiece being rolled, the hardness of the metal material and the roll pressure allowance.

Why is rolling technology used so widely in precision machining?

The roller burnishing process is a kind of non-chip processing, and the whole process can be accomplished by applying pressure to the surface of the workpiece by a certain form of rolling tool. Roller burnishing tool is at room temperature using the principle of the metal plastic deformation, rolling flat surface uneven places, to change the surface structure, mechanical properties, shape and size to achieve the effect. Therefore, this method can achieve smooth processing and strengthen two purposes at the same time. The surface strength of metal workpiece is strengthened after surface rolling, and the performance of workpiece, fatigue strength, abrasion resistance and corrosion resistance are obviously improved. After rolling, the hardness of the workpiece can be increased by 15 ~ 30%, while the wear resistance increases by 15%.

Rolling processing can increase surface roughness from Ra6.3 to Ra2.4 ~ Ra0.2. And there is a high production efficiency, some of which can be completed in a few minutes or seconds.

Rolling process can solve some key problems which are not easy to be realized. For example, the machining of a large cylinder block. At the same time, it is also suitable for the finishing machining of special holes or the finishing process of some special materials.

Rolling process is widely used in all large, medium and small factories. In terms of processing quality, production efficiency, production cost and other aspects, roller burnishing process is a superior processing method. In some respects, it can completely replace fine grinding, grinding and honing.

At present, the processing method of the rolling tool by external force can be divided into three types: mechanical, rolling and spring.

According to the processing nature, it can be divided into light finishing and intensive processing.

The roller burnishing tool has the advantages that the machining center does not have. Because the roller burnishing tool can be simple and low cost to carry out the ultra-precision machining of parts. It has been widely used in the automotive industry, such as precision machinery, chemical and household appliances.