Process of steel barrel quality (V)
3. uneven flanging
in production practice, uneven flanging is also common. It is mainly manifested in that the flanging width around the barrel body varies from wide in some parts to narrow in some parts. If the wide part is higher than the edge of the barrel bottom, false curling will occur; If the narrow part fails to meet the requirements of the process standard, there may be curling gap. In both cases, the size of the investment scope can cause serious leakage.
4. mechanical damage at flanging
mechanical damage occurs during the turnover between processes, which is not easy to occur in the production environment where the workpiece of the automatic production line does not fall to the ground. For different damage processes, the asset management personnel of the user unit shall issue the notice of mechanical equipment maintenance and lubrication, and the degree of arrival at the operation team may have different effects on the sealing, and the greater the degree of damage may cause quality problems such as false coils and iron tongue. Cracking at flanging
5. there are two cases of flanging cracking. One is that transverse cracks occur during flanging due to the effect of material hardening and embrittlement; One is that sometimes the flanging width is seriously over wide, the welding is not firm or the longitudinal crack will appear when it is burnt. These two kinds of flanging cracks will cause leakage during flanging and sealing. Vi. barrel bulging process problems
barrel bulging generally does not have too many quality problems. Sometimes there is an error in size, which will not affect the actual quality. However, in some cases, more serious problems may occur. Expansion crack
1. when the material is brittle and hard and the seam welding is scorched, cracks will appear at the top of the expansion bar during the expansion process, resulting in leakage. Sometimes, the stirrup may be too high during expansion, resulting in excessive deformation and cracking. The crack will directly lead to leakage at the crack.
2. weld tearing
in the case of false welding, the expansion process treatment may cause weld tearing or expansion reinforcement stretching. These control systems for weld tearing include 3 closed-loop control, which can only be treated as scrap. Those stretched at the expansion bar can be repaired by repair welding and treated as repaired products. VII. Problems in the assembly process of the sealing system
the assembly process of the sealing system is the most critical process in the production of steel drums. However, most people in the industry pay too much attention to the importance of this process. As long as there are quality problems such as sealing leakage, they will find the causes in the sealing process and blindly drill the ox horn to study the groove type of the edging roller. In fact, a large part of the problem of the sealing quality lies in the groove shape of the roller, but more problems lie in the materials and related processes.
in fact, the shape of the crimping groove is not unique. Different enterprises' materials, processes and equipment will lead to different roller sizes. As long as they adapt, no one will make a roller groove that everyone can adapt to. In order to solve the hot topic that everyone is studying, the author, together with the professors of Gansu University of technology, conducted a simulation test with a large computer and found that the most ideal roll groove curve was actually an involute. In practical application, only the middle section of the roll groove curve can be used, and the other starting and ending sections are designed for feed guidance, forming size and shape. But the middle segment is very important, which determines the curling trend. Under the guidance of this trend, curling will easily enter a more ideal curling state
in fact, based on the results of this involute, the forming principle of the involute will be naturally associated with the curling process. Because the formation of involute and the steel barrel curling process are mutually inverse, they are the same curve, but in the opposite direction. Therefore, it is not difficult to prove the theoretical correctness and practicality of this curve
the quality problems that often occur in the process of edge curling and sealing mainly include: insufficient layers of edge curling, loose and false edge curling, iron tongue, etc
1. insufficient number of crimping layers
quality problem of insufficient number of crimping layers plastic stress and deformation curve usually includes one linear elastic region and one non-linear plastic region, which may be caused by the following reasons: improper groove of crimping roller, out of tolerance of barrel flanging size, insufficient pressure of sealing machine pressure plate, etc. The improper groove of the edging roller is relative, because it is related to the thickness and material of raw materials. Different material thicknesses correspond to different rollers. For materials with uneven thickness, this situation often occurs because the rollers cannot adapt. When the flanging of the barrel body is too narrow, the flanging material is insufficient, and the winding layer is certainly insufficient. When the pressure of the pressure plate of the sealing machine is insufficient, due to the pressure of the roller during the crimping process, part of the crimping material can return to the barrel body or the barrel cover, so that the crimping material is insufficient. (to be continued)