Process Analysis of Steel Bar Deformation Quality Problem

Process Analysis of Steel Bar Deformation Quality Problem

Yang Wenliang

In the finished steel drums, we often find that some steel drums have different forms of deformation. These deformations greatly affect the appearance quality of the steel drums. It is a good product that has become a non-conforming product, and even piled up for a long time. Asked, caused a great waste. The reasons for the deformation of the steel drum are various, mainly related to the production process. In the long-term production practice, we gradually mastered its laws and tried to reduce the occurrence of deformation. Below, we focus on analyzing several common deformations.

First, the top of the barrel is not flat

In some steel drums, there is a phenomenon of deflection, which usually appears as a wave. The reason for this phenomenon is related to the stamping of the bottom cover of the barrel.

1. When the bottom cover is stamped, because the blanking force around the mold is not uniform, in the deep drawing process, some parts are pulled into more materials, and some parts are pulled into less material, so that the material internal stress is generated at the top of the barrel. Uneven phenomenon. If the contrast direction of the internal stress coincides with the direction of rolling of the material, internal stress deformation is easily generated, and the deformation causes the top of the barrel to be wavy. This deformation can be solved by equalizing the pressure.

2. When the mold draws unevenly, the same stress deformation will occur in the above case. This deformation can be solved by adjusting the mold drawing clearance.

3. The raw materials themselves are not deflected. Some coils are not machined flat during unwinding, resulting in unevenness after stamping. There are also some products that use uneven secondary materials, and naturally there will be no good products.

4, the bottom cover favorite process in the process of turnover or bruises in the subsequent process.

Second, the barrel is concave

The concave inside the barrel is on the surface of the cylindrical barrel, and there is an inwardly concave pit, which makes the steel barrel obviously out of round. The reason why the newly used concave is generated is many, and the main cause is mechanical damage and physical damage.

1. Mechanical damage is mostly generated during the production process of the barrel. Generally, when the assembly process of the steel drum is about to end, the steel drum cannot be made because the bottom of the barrel is covered (the bottom of the barrel or the top of the drum is wrapped). Remove the position of the roll-up roller in time to eliminate the phenomenon of the package, so as to avoid deformation of the barrel.

2. The steel drum after the package is packaged, in the process of transportation in the subsequent process, the steel barrel collides and falls due to poor operation. This situation should be solved by improving the production environment and increasing the buffering facilities. At the same time, it is necessary to enhance the civilized production awareness of the operators.

3. The physical damage of the steel drum is mostly formed in the steel drum painting process. After the steel drum is painted, it enters the drying oven to dry. Because the barrel is relatively sealed, the air inside the barrel is under the effect of high temperature in the furnace. And the water gradually evaporates, expands, and the internal pressure increases, and the internal gas can generally be discharged through the tightly sealed barrel mouth. After the steel drum emerges from the oven, the turnover cap is generally replaced and tightened with a formal barrel mouth piece at this time. When the steel drum leaves the production site, it gradually cools down, and the internal pressure gradually decreases. When the internal pressure is less than the external pressure, the barrel body is prone to invagination due to the pressure difference. The solution is to tighten the barrel when the drum is cooled.

Third, the barrel body deformation

In the processing of steel drums, the barrel body is often turned into a shape of gossip. The deformation of the gossip is most obvious on both sides of the large ring of the barrel, the ring is narrowed, and the sides of the ring are indented. Such deformations are often produced in the production process, and the causes are the deformation of the barrel body, the influence of the quality of the raw materials, the adjustment of the crimping assembly and the influence of the size of the barrel blank.

1. The size of the blank is too small. When the length of the barrel body is too small, the inner diameter of the barrel body is smaller than the standard. When the barrel body is formed and crimped, the inner diameter of the barrel body is small and cannot smoothly enter the flange mold and the sealing tray, and the equipment has been set and processed. The position can not be changed at any time, so the barrel body is forced to reach the predetermined position under the pressure of the two ends of the barrel, so that the barrel body can only achieve this purpose if it has its own internal deformation. The solution is only effective by controlling the size of the blank.

2. The seam welding edge is too wide. When the seam welding edge size is too wide, the inner diameter of the barrel body will also become smaller, which is similar to the above-mentioned blanking size being too small. Can be solved by controlling the size of the lap.

3. The problem of the barrel forming equipment. Some barrel forming equipments use hydraulic principle to complete the work of flanging, bulging, and expanding ring ribs. In the device adjustment, the operation program is confused for some reason. For example, the flange should be expanded first, then the program becomes the opposite state, so the movement position is staggered, because the flange force is larger and the ends of the ring are weaker due to the bending, thus creating the ring The indentation of the end is deformed. Just fix the action program to solve this problem.

4. The pressure of the crimping machine is too large. When the pressure of the two plates of the crimping machine is too large, the adjusted pressure plate forming position is smaller than the height of the barrel body, so that the barrel body has been pressed to the required height and continues to be squeezed, so that the indentation is deformed. Properly adjusting the forming distance between the two plates can solve the problem of excessive pressure.

5. The thickness of the raw materials is uneven. In the production process, the thickness of the steel drum material is often uneven, which is especially common in hot rolled sheets. When the device is timing. Occasionally, when it encounters a thinner material, its resistance to the processing force is relatively reduced, and it is easily deformed under the pressure set by the raw material. This deformation is more difficult to avoid in the case of uneven material thickness. Where conditions permit, the materials can be classified by thickness and then separately organized for production.

Fourth, the curling circle is missing

In the finished barrel, we often find that some steel drums are collapsed and rounded out. This phenomenon is mostly caused by falling, bumping, falling, bumping, etc. during the production process. This situation can only be solved by strengthening safe and civilized production and by setting up necessary station equipment and adaptive handling tools.

For steel drums that have been deformed, the necessary repairs can be made. Generally, the deformation of the barrel body can be repaired by a hydraulic method, that is, high pressure water is input into the barrel, and the invaginated portion is bulged outward with a high pressure to achieve the purpose of restoration. In the case of the rounding of the curling, the same method as the old barrel retreading can be used for repairing, that is, the bulging of the barrel is used to expand the circle.