Analysis of materials and process problems affecting the quality of steel drums (1)

Yang Wenliang

The quality of steel drums has always been one of the eternal topics in the steel drum industry and one of the problems that have long plagued barrel makers. The reason for this is that most of the reasons are that we have not systematically studied and managed related technologies and processes. The establishment of ISO9000 quality system provides a strong guarantee for the improvement and stability of steel drum quality. With the support of this powerful system, we can adopt a scientific attitude and systematically study the actual quality problems inside the steel drum. Through the seamless quality assurance of ISO9000, we can realize advanced technology and scientific craftsmanship. Strong combination.

The main quality problem of steel drums is the leakage of steel drums. This is the key to the qualification of steel drums and the key to technology and technology. This is the focus of our research.

There are many technical problems affecting the quality of steel drums. If you look up and analyze them separately, you will see that the trees do not see the forest, which is not conducive to the solution of the problem. Through long-term practice and research in the steel drum industry from technology to production, we find that these technologies and processes have intrinsic relationships, mutual influence, mutual unity and mutual connection. Therefore, it is necessary to carry out all-round interactive analysis. Only in this way can we find the essence of quality problems and achieve the three unifications of technology, technology and quality.

Using the process interaction impact analysis method, we can see how the impact of each process in the steel drum production process affects, how it can be affected or less affected. Because most of the process problems do not seem to directly affect the final quality, but after using the interactive impact analysis, it will find that it will have a certain impact on other processes, thus affecting the final product quality.

Steel drum production technology is actually a comprehensive technology, production seems simple, but it involves a wide range of technical fields. For example, unwinding and leveling of coils belongs to steel rolling and shaping technology; barrel body grinding (or milling) is a metal cutting technology; barrel curling is a sheet metal processing technology; spot welding and seam welding are welding techniques; The essence of the sealing technology; the production process of the bottom of the barrel and the barrel mouth are cold stamping technology; the degreasing and derusting of the barrel is a chemical surface treatment technology; the painting of various methods of the steel barrel belongs to the metal surface coating technology; The drying process of the coating film belongs to the far-infrared heating technology and other heating technologies; the patterning on the finished steel drum belongs to the printing technology category, etc., etc., such as rolling technology, calendering technology, hydraulic transmission, etc. Technology, pneumatic transmission technology, expansion technology, automatic control technology, etc. Therefore, barrel technology is not a separate discipline, we must relax and study carefully.

Now, let us use the interactive influence analysis method to carry out the necessary analysis of the main process. Due to the relationship between the lengths, we can't elaborate on the process. We pay attention to the analysis of analytical methods and mutual relations, in order to play a role in attracting The role.

First, the raw material problem affecting the quality of the process

In order to ensure the quality of the products, we must first ensure the quality of the process, but to meet the quality requirements of the process, the guarantee of the quality of raw materials bears the brunt.

The main raw material for steel drums is steel plates, and the auxiliary materials are sealants, gaskets, barrel parts and paints. The most important material affecting the quality of the process is the steel plate.

The requirements of the barreling process on the steel sheet are generally flat surface, low hardness (small rigidity), small carbon content and uniform thickness. Of course, the most suitable is how it relates to the equipment status of each manufacturer. There is also a problem of quality cost, so you can't be high. As long as the minimum process requirements are met. Below we analyze the problems that are often generated when the raw steel sheets are not suitable for the barrel making process in production practice.

1. The surface of the steel plate is not flat

When the surface of the steel plate is warped, the size of the barrel may be out of tolerance. After the seam welding, the diameters of the two ends may be inconsistent or the seams may be misaligned.

When the diameter of the barrel is too small, it will affect the joint when it is wound with the top of the bottom of the barrel. The amount of the bottom of the barrel can not be put into place, which causes the quality of the material to be insufficient, and the curling is not real.

When the diameter of the barrel is too large, it is loosely fitted with the top of the barrel at the time of sealing, and the gap is too tight, and the barrel is wrinkled, resulting in leakage or surface quality problems.

The misalignment of the seam welding edge causes the stepped edge to be unequal in the burring process, and the edging edge is insufficient in the size of the burring, which affects the insufficient material of the hem in the winding process and the number of layers is insufficient. The quality problem of curling is not true.

When the surface of the steel plate is warped, the quality of the bottom of the barrel is difficult to ensure, and the warping of the top of the barrel may occur, which may affect the degree of compression in the winding. For the open top bucket lid, the warpage is unusual and causes assembly problems. Due to the influence of the roundness of the blanking, uneven edging of the surrounding area may also occur, which may also affect the quality of the sealing of the closed barrel and the sealing joint of the open barrel lid, which may cause leakage of the steel drum.

2, the steel plate has high hardness and rigidity

The hardness of the steel plate is high, and the rigidity is mostly caused by the large carbon content and the heat treatment. For the barreling process, it directly affects the quality of the process.

When the hardness is too large, the steel plate rebounds greatly, and the radius of curvature of the barrel is too large, which affects the seam welding positioning of the next process; in the flanging process, since the rebound is too large, the angle of the cuff can be made Too large, the size is reduced; in the winding process, the curling edge will also cause gaps in the curling edge, and the quality problem of curling is not real.

Due to the large rebound, the quality of the barrel mouth lock on the steel drum lid will also be affected, and leakage may occur in the gap.

3. Steel has a large carbon content

Steels with too much carbon will cause problems with high hardness and rigidity. In addition, the high carbon content will have a great influence on the quality of the seam welding of the barrel, which will make the material of the welded part become brittle, and cracks will occur in the process of the subsequent flanging and expansion, which is the leakage quality problem of the steel drum. The biggest hidden danger.

4, the thickness of the steel plate is uneven

Plates with uneven thickness are a taboo for barrel production.

The thickness of the steel plate is uneven, and the seam welder will be at a loss, because the various parameters of the seam welder adjusted in the production have been determined. When the steel plate is thick and thin in production, the parameters are not automatically adapted, so the welding occurs. Quality problems, you must wear it, you must not solder.

The thickness of the steel plate is uneven, and the problem of the hemming assembly is greater because a shaped crimping roll can only accommodate a steel plate of one thickness. For ultra-thick steel plates, the roll grooves are small and cannot be installed; for ultra-thin steel plates, because the roll grooves are large and unsatisfactory, these two conditions will certainly cause more leakage.

The thickness of the steel plate is not uniform. For the stamping process of the barrel, the workpiece size may be excessively deformed or deformed, and the damage of the tool or the life may be reduced.

5. Influence of auxiliary materials on process quality

Inappropriate auxiliary materials are sometimes an important part of the quality of the steel drum process.

Crimping sealant requires better elasticity, higher bonding strength, more curing components, better chemical resistance and better process performance.

The elasticity is good, in order to seal the force during the sealing, it can have a certain amount of compression. Because of its good elasticity, it has a certain resilience. With this resilience, it can squeeze the crimping gap and improve its Sealing performance.

The adhesive force is strong, so that the rubber ring pre-sprayed on the top edge of the bottom of the bucket is firmly adhered to the beading edge, and the wind seal is not easy to fall off when it is rubbed by an external force with the flange of the barrel.

Most of the curing ingredients are for actually filling the gaps in the curling edge. Some of the curing components of the glue are too small, and the wet glue is sprayed a lot, but the curing is minimal and the filling effect is not achieved.

The chemical resistance is good, so that the sealant does not react adversely with the contents of the steel drum, and some reactions may cause the sealant to fail, and some reactions may deteriorate the contents.

Good process performance, mainly refers to the construction process, some sealants, other properties are good, but the construction performance is not good, such as not easy to spray, brush, dry, etc., will cause difficulties in construction, thus affecting the use; some glue in steel drums When entering the drying furnace to carry out the drying of the paint film, there are phenomena such as burning, thinning and flowing, which have an effect on the sealing performance of the crimping.

The sealing gasket on the barrel mouth piece has a certain elasticity to make the sealing performance better. The chemical resistance of the material is also very important, which is the same as the requirement of the sealing glue, mainly for not causing the chemical reaction between the gasket and the contents. Corrosion, thereby affecting its sealability or contaminating the contents.

The quality of the barrel mouth itself also affects the sealing performance and interchangeability of the steel drum.

The outer coating of the steel drum only affects the quality of the appearance, but it has the greatest impact on the safety of the contents for the internal coating of the inner coating barrel. The adhesion and chemical resistance of the paint are the most important. The processability determines the difficulty of the construction and the effect of the coating. If the quality requirements of the interior coating are not met, the contents will undoubtedly cause damage.