defect, it is a manufacturing defect, perhaps almost all products.Speaking briefly, this production, which is not allowed to the consumer because of the mismatch with their requirements.For example, non-sealed packaging, insufficient weld strength and so on.Let us talk in more detail about what the defects, as well as consider the types of defects of various materials.
Any industry in varying degrees produces defective products, that is defective.As a rule, marriage is determined after sending to the warehouse or to the consumer.In this case, the manufacturer may either withdraw their products and leave it.For example, defective packaging for household sponges can not be considered critical, but the marriage is in the brake system of a vehicle could result in death of the driver.Therefore, it should be understood that the defects are different: some are valid, others - no.You can talk about that any product which has at least one deviation from established norms, it is considered defective,
Types of defects in construction
Sometimes on the news we hear information that somewhere collapsed house collapsed masonry and so on. N. Often, the culprit becomes a defect that was not detected during verification.For example, in the construction industry, any discrepancy with the terms of reference (TOR), or the established rules known as design defects.If we are talking about non-compliance of the technical documentation for the manufacture of products, it is called a manufacturing defect.But that's not the entire list.The fact that in the construction and other defects occur.Types of defects here are classified as follows:
- obvious defect is determined by external examination, ie visually;
- latent defect does not provide control standards.It is usually detected after sending the goods to the consumer.
can say that the obvious defect is less dangerous for the consumer, because it is much easier to detect and correct.However, not always obvious defects are eliminated by the manufacturer.You can often buy products that are not visually correct, for example, having chips on its surface, leaking packaging and so on. N.
critical, significant and unimportant defect
All these types of marriage can be conditionally placed in the same group,since they are interrelated.The fact that such a discrepancy, anyway affect the efficiency of production, but to a different extent.For example, the critical marriage suggests that the effectiveness of the goods, depending on the application, will be much lower.Typically, use of the product for its intended purpose in this case is not possible or not allowed.As an example, a broken kitchen knife, leaky compressor for compressed air supply, and so on. N.
major defects - is one that is not critical, but has a significant impact on the durability and efficiency of use of the product for its intended purpose.For example, microcracks in the metal sheet is considered significant defect.Such defective products can be used, but not as long and not under a heavy load.Minor defect - one that does not affect the durability and efficiency of production.For example, worn paint on the radiators is considered a minor defect.
Types of weld defects
is difficult to underestimate the importance of welded joints.Agree, they determine the quality of the product as a whole.For example, well-cooked solid fuel boiler body looks much better than the one on which the identified defects.Types of defects in welding operations are divided into external and internal marriages.The first is determined visually, and the second can only be found during the inspection.
Furthermore, in this case we can speak of acceptable and unacceptable defects.Group goods valid marriage can be used with efficiency less than 100%, the second group to the user is not allowed.However, the defect itself - it is something abnormal, requiring removal.Today, defects in welds eliminate, using modern welding technology and allowing to work only skilled craftsmen.In addition, add special filler materials, used welding equipment and much more.Let's take a closer look at types of product defects (weld) and how they affect the efficiency and safety of products for consumers.
Any violation of the geometry of the structure is called an external defect.These should include the rush, lack of fusion, undercut and others. Almost all of this is determined by eye.For example, the main reason is the lack of penetration a small arc metal penetration.This is due to insufficient power.Corrected this defect is very simple: try to increase the dynamics and decrease the length of the arc.In addition, the marriage often occurs because of too rapid execution of works, so sometimes it makes sense to do a weld measured.
Another typical and most common defect - undercut.This marriage, which is a groove (recess) in the parent metal around the joint.Usually it formed due to improperly selected current and welding speed.Basically, a lot depends on the human factor.
burn-through is also quite common.This defect is a through-hole in the weld.Sometimes marriage because too slow and large welding current.As a result, leak of the weld pool.
influx occurs as a result of the scale on the surface at the wrong mode is selected welding.Such a marriage is a leakage of the additive in the base metal without melting.
This kind of marriage is detected less frequently, as detected with the naked eye can not everyone.That is why there is often a failure of welded construction, which can be very dangerous to humans.One of the most common and dangerous defects - hot crack.They can be both longitudinal and transverse.Occur in an intermediate period of melting and solidification of the metal, as well as because of an error when selecting the additive material and its chemical composition.Responsibility for such defect falls squarely on the shoulders of the welder.There are also cold cracks.They arise after the solidification and cooling of the weld.Usually there due to excess load on the joint.
pores - a defect that appears in all types of welding.It's safe to say that such problems faced every welder.If you list all the major types of defects in welded joints, this will in the first place.There it is due to the lack of protection gas welding bath.As a result, the pores are formed, which differ in size and random distribution.
tissue defects in the manufacturing process of any product there is a marriage.Weaving is no exception.There are a variety of types of tissue defects, which we now try to see.The most common marriage - is close.It implies a lack of one or more threads on a certain length.Often this defect appears because of thread breakage during the work.This is due to a malfunction of the lamellar device or as a result of operator error that stopped the machine later than necessary.It is interesting that this type of defect is not taken into account, if it is on the closed parts of the product.This sale is prohibited products with a close 10-20 cm in two strands.
often meets and knotting.This defect is a failure of one or two strands and sealing them into the fabric.As a result the product in place sealing becomes irregular.Such a defect is not valid for products of the 1st and 2nd grade.Defect called "yarn nepodrabotka" affects the quality of products as well as knotting.Is a defect that the warp yarns are not interwoven with the weft yarns, whereby the cloth provided on the surface, changing its shape.Marriage associated exclusively with the weaving machine malfunction, called Nedosekov.It consists in the presence of weft allowed bands.
Other tissue defects
There are other types of defects in products made of fabric.But first it is worth noting that the flaw is a local (local) and the common.The first is usually small and is only in the specific area of the product.These defects can be attributed Blizna, knotting.But defects propagating along the entire length of a piece of cloth, called common.These usually include debris, banding and others. Another interesting point is that all these defects can occur at different stages of production.Thus, the defect can appear more in spinning due to the insufficient quality of raw materials, or even at the finish.All of this suggests that requires careful control at all stages.In addition, it is necessary to purchase only quality raw materials.The same applies to the weaving equipment and, in fact, the qualification of employees.
For example, the presence of dirt and oily stains depends on the profusion of grease machine.And since the equipment is lubricated automatically, the operator does not make sense to blame.The same applies to holes, embossments, and the holes on the product, which appear as a result of incorrect operation of the machine.Such goods do not pass quality control and immediately married.It is necessary to draw your attention to the fact that in the weaving business there to eliminate the defects.Local defects in any case lower grade, but when cutting tissue they can circumvent by implementing supply of the highest grade.
defects of metal and metal products
To date, there is no defect-free metal samples.This suggests that to some extent there is a marriage.But the interesting thing is that as a result of occurrence of certain processes and performance of mechanical operations, the quality of the metal may drop significantly, so that the product comes complete unsuitability for further use.
most common defects that occur during the deformation of the metal in the solid state.The smaller the deformation, the minimal number of defects appears.Some steels have good elasticity, it allows a small deformation after taking his old form.However, if you continually improve the load, the turning point will come when it will be impossible to recover the metal.In any case, it makes sense to say that here, as in weaving, certain types of metal defects still occur during casting, while others are already in the final processing of the product.
For example, casting defects occur very often.In the metallurgical industry, with them trying to struggle constantly developing new ways of casting.The unevenness of cooling and solidification of the molten metal leads to the fact that the pores are formed and shifts the inner layers.Also, there are various kinds of defects in components undergoing secondary machining and heat treatment.There is also a marriage that occurs during transportation or storage of metal products.
Conclusion As you can see, there are a variety of defects.Types of defects in metal, welded joints and tissues, we have examined.But you must understand that marriage is present in the food and chemical industry.There can not even talk about the human factor, since the machine is also sometimes give a failure that leads to a similar result.However, some types of product defects can be eliminated partial or full automation of the process that is currently and produced.
As for the buyer as the final consumer, it is not worth buying defective products.Often they offer a discount and other attractive offers.This makes sense only if the purpose of the product is not of a responsible nature, in other cases, any defects can lead to unexpected and even tragic consequences.So before you buy anything, make sure as a commodity, as well as its good.Even a small error in the manufacturing process can cost you good health and often and life.