Weld cracking
Different types of connectors may be placed in the weld or heat affected zones occur. Welds may contain porosity, slag or Khalhay are all Turks . Khalhay weld porosity and slag may be acceptable to some extent , but never cracks in welds are not acceptable . Cracks in the weld or near the weld indicates that probably there is a problem at work . Turks examination to determine the cause and ways to prevent them Ajad makes them for us . First, we should note that we distinguish between crack and break . To our left , a phenomenon that is caused by factors such as freezing , cooling and internal stresses due to shrinkage of the weld is created . Turkish hot cracking , which are occurring at high temperatures and are usually associated with freezing .
Cold cracks are cracking after welding to reach room temperature , and may occur even if the HAZ interface .get cracking . In fact , there are two opposing forces :
1 . Tension is created by the contract .
Two . Strength and stiffness of base metal
Stresses caused by the volume shrinkage of metal that is placed under tension increases. Large -scale processes influence rash and muscle strain increases . Stresses caused by shrinkage strain is caused by the increasing strength of the filler metal and the base metal increases. The yield strength increases when the residual stress increases .
1 . Need for welding
Two . Preheat
Three . Temperature pulsed
4 . Heat treatment after welding
5 . Design Connection
6 . Welding methods.
7 . Filling
Leave a central line
Leave a central line in the center of a weld pass is given . If you have acne and Aynpalydrmrkz Kpas terminal connection , then the appointment will also Trkmrkzy in Mrkzatsal . Pass the few places where there are several layers of fine cracks in the center of Hndsyb may not be connected at the center . From what is often seen in Mrkzatsal . Leaving the center of one of the following three phenomena :
1 . Turkish is the result of segregation and discrimination .
Two . Turkish is the shape of the weld bead .
Three . Turkish is the surface changes .
Unfortunately, all three of these phenomena manifest themselves in the form of a kind and is difficult to distinguish withdrawal . In addition , experience has shown that often 2 or even 3 of these phenomena interact with each other and contribute to cracking . Understanding the basic mechanisms of a variety of central cracks helps us to seek a solution to eliminate the need to leave .
Head left from the separation
These cracks occur when the compounds with low melting point such as phosphorus , zinc , copper and sulfur are separated at some point during the cooling process . Welding electrodes with high levels of manganese can be used in order to overcome the low melting point to form iron sulfide . Unfortunately, this concept of non-volatile substances other than Sulphur can be used .
Head left from the weld
The second type of center left , leaving the pimple is caused by the pulse shape , this left a deep influence on the processes that are associated with processes such as FCAW, SAW is observed under CO2 shielding . When pulse welding has a greater depth than the boiling digestion ( in view of the cross section ) is. To fix these cracks, weld pulse width must be at least equal to the depth . It is recommended that the width of welds to a depth equal to 1 to 14/1 to be the first to leave it to be resolved . If you are using multiple pulses per pass Nbt width to depth is not a welds will crack . When the steam passes from a central crack under review , the only solution is to change the depth of the weld width .
It may be that covers the design changes have connections . Since the penetration depth is a function of the weld may be useful in order to reduce the amount of Mprhay lower electrodes with diameters greater than we can . This strategy reduces the influence of current density limits .
Head left from the boiling surface conditions
Last mechanisms that cause changes in surface condition is left of center . When the rash is caused by stress -induced contractions with an inner concave surface causes the surface to be welded up . Conversely, when the electrode surface is convex inner force of contraction , causing the weld surface is pressed . Concave weld surface , is often caused by high voltage arc . Causes a slight decrease in arc voltage convex weld bead shape and tend to leave the state to be removed . Welding in vertical down the cause of this type of leave . In the case of vertical upward welding can prevent the occurrence of this type of leave .
Leave the area affected by acne
Leave weld -affected zone (HAZ) is characterized by segregated occurs immediately adjacent to the weld , although the type of leave, the welding process is however not occur in Turkish , which is based on the weld itself . This leaves one adjacent to the weld , leaving aside also called delayed or abandoned . Leave the steel after it has been frozen at f 400 , also called freeze- out occurs when the hydrogen is combined with hydrogen , also called withdrawal . The HAZ cracking occur simultaneously three conditions must be established :
1 . Should there be a sufficient amount of hydrogen .
Two . Welds must be sufficiently permeable .
Three . Should there be enough residual internal stresses .
Remove one of the above three conditions is usually left it to go away. In welding , a way to remove it is to leave two or three variables ( the permeable electrode welding ) to limit . Hydrogen can be imported from various sources was boiling . Moisture and organic compounds are the main sources of hydrogen in the weld . Hydrogen can be used in steel electrode , the electrode and the atmosphere there is Trkyybat gowns .
Transverse cracks
Leave a transverse crack is also called a crossover . Turkish in the direction perpendicular to the weld is created . This type of cracking is often in a variety of fusion welding face and we usually have a higher strength than the base metal is seen . This type of leave can be combined with hydrogen to leave the area affected by the amount of weld HAZ arising from the previously described hydrogen , residual stresses and microstructures is sensitive .
Leave the major difference between the two is that the transverse cracks in the weld residual stress is longitudinal . As long as the contract will pass welding , the base metal and the strength of the force density and compaction is developed . To prevent the base metal leads to stress in the weld length is extended .
When we are faced with transverse cracks in the surface of the electrodes , hydrogen and storage conditions to keep in mind . In the case of transverse cracks , reducing the strength of the weld metal is usually one of the solutions to eliminate this type of leave . There is a lot of stress on the weld filler metal, weld deposits that alone may be a lower strength under normal circumstances is a soft metal . However, the effect of alloying elements increases the weld strength and plasticity is reduced. Rash with lower strength of a solution is effective in reducing crack width , the conditions of the weld strength is consistent with defined standards .
Different types of connectors may be placed in the weld or heat affected zones occur. Welds may contain porosity, slag or Khalhay are all Turks . Khalhay weld porosity and slag may be acceptable to some extent , but never cracks in welds are not acceptable . Cracks in the weld or near the weld indicates that probably there is a problem at work . Turks examination to determine the cause and ways to prevent them Ajad makes them for us . First, we should note that we distinguish between crack and break . To our left , a phenomenon that is caused by factors such as freezing , cooling and internal stresses due to shrinkage of the weld is created . Turkish hot cracking , which are occurring at high temperatures and are usually associated with freezing .
Cold cracks are cracking after welding to reach room temperature , and may occur even if the HAZ interface .get cracking . In fact , there are two opposing forces :
1 . Tension is created by the contract .
Two . Strength and stiffness of base metal
Stresses caused by the volume shrinkage of metal that is placed under tension increases. Large -scale processes influence rash and muscle strain increases . Stresses caused by shrinkage strain is caused by the increasing strength of the filler metal and the base metal increases. The yield strength increases when the residual stress increases .
1 . Need for welding
Two . Preheat
Three . Temperature pulsed
4 . Heat treatment after welding
5 . Design Connection
6 . Welding methods.
7 . Filling
Leave a central line
Leave a central line in the center of a weld pass is given . If you have acne and Aynpalydrmrkz Kpas terminal connection , then the appointment will also Trkmrkzy in Mrkzatsal . Pass the few places where there are several layers of fine cracks in the center of Hndsyb may not be connected at the center . From what is often seen in Mrkzatsal . Leaving the center of one of the following three phenomena :
1 . Turkish is the result of segregation and discrimination .
Two . Turkish is the shape of the weld bead .
Three . Turkish is the surface changes .
Unfortunately, all three of these phenomena manifest themselves in the form of a kind and is difficult to distinguish withdrawal . In addition , experience has shown that often 2 or even 3 of these phenomena interact with each other and contribute to cracking . Understanding the basic mechanisms of a variety of central cracks helps us to seek a solution to eliminate the need to leave .
Head left from the separation
These cracks occur when the compounds with low melting point such as phosphorus , zinc , copper and sulfur are separated at some point during the cooling process . Welding electrodes with high levels of manganese can be used in order to overcome the low melting point to form iron sulfide . Unfortunately, this concept of non-volatile substances other than Sulphur can be used .
Head left from the weld
The second type of center left , leaving the pimple is caused by the pulse shape , this left a deep influence on the processes that are associated with processes such as FCAW, SAW is observed under CO2 shielding . When pulse welding has a greater depth than the boiling digestion ( in view of the cross section ) is. To fix these cracks, weld pulse width must be at least equal to the depth . It is recommended that the width of welds to a depth equal to 1 to 14/1 to be the first to leave it to be resolved . If you are using multiple pulses per pass Nbt width to depth is not a welds will crack . When the steam passes from a central crack under review , the only solution is to change the depth of the weld width .
It may be that covers the design changes have connections . Since the penetration depth is a function of the weld may be useful in order to reduce the amount of Mprhay lower electrodes with diameters greater than we can . This strategy reduces the influence of current density limits .
Head left from the boiling surface conditions
Last mechanisms that cause changes in surface condition is left of center . When the rash is caused by stress -induced contractions with an inner concave surface causes the surface to be welded up . Conversely, when the electrode surface is convex inner force of contraction , causing the weld surface is pressed . Concave weld surface , is often caused by high voltage arc . Causes a slight decrease in arc voltage convex weld bead shape and tend to leave the state to be removed . Welding in vertical down the cause of this type of leave . In the case of vertical upward welding can prevent the occurrence of this type of leave .
Leave the area affected by acne
Leave weld -affected zone (HAZ) is characterized by segregated occurs immediately adjacent to the weld , although the type of leave, the welding process is however not occur in Turkish , which is based on the weld itself . This leaves one adjacent to the weld , leaving aside also called delayed or abandoned . Leave the steel after it has been frozen at f 400 , also called freeze- out occurs when the hydrogen is combined with hydrogen , also called withdrawal . The HAZ cracking occur simultaneously three conditions must be established :
1 . Should there be a sufficient amount of hydrogen .
Two . Welds must be sufficiently permeable .
Three . Should there be enough residual internal stresses .
Remove one of the above three conditions is usually left it to go away. In welding , a way to remove it is to leave two or three variables ( the permeable electrode welding ) to limit . Hydrogen can be imported from various sources was boiling . Moisture and organic compounds are the main sources of hydrogen in the weld . Hydrogen can be used in steel electrode , the electrode and the atmosphere there is Trkyybat gowns .
Transverse cracks
Leave a transverse crack is also called a crossover . Turkish in the direction perpendicular to the weld is created . This type of cracking is often in a variety of fusion welding face and we usually have a higher strength than the base metal is seen . This type of leave can be combined with hydrogen to leave the area affected by the amount of weld HAZ arising from the previously described hydrogen , residual stresses and microstructures is sensitive .
Leave the major difference between the two is that the transverse cracks in the weld residual stress is longitudinal . As long as the contract will pass welding , the base metal and the strength of the force density and compaction is developed . To prevent the base metal leads to stress in the weld length is extended .
When we are faced with transverse cracks in the surface of the electrodes , hydrogen and storage conditions to keep in mind . In the case of transverse cracks , reducing the strength of the weld metal is usually one of the solutions to eliminate this type of leave . There is a lot of stress on the weld filler metal, weld deposits that alone may be a lower strength under normal circumstances is a soft metal . However, the effect of alloying elements increases the weld strength and plasticity is reduced. Rash with lower strength of a solution is effective in reducing crack width , the conditions of the weld strength is consistent with defined standards .
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