Understanding How to Repair Alloy Steel Pipe

The time of issue:2014-6-12 11:04:29       Author:

The amount of carbide aggregate in API steel pipe is without any doubt expected to be remained in the range of two percent to three percent. In fact, optical API steel pipe does not have enough resolution to correctly identify the micro structures on the API steel pipe metal and it only becomes clear with the aid of further analysis. To be more specific, a qualitative analysis shows that a higher content of micro constituents in the API steel pipe is usually followed by harmful effect on the metal toughness, which means that normalized micro structure might not be good news for API steel pipe all the time.

On the other hand, how to repair alloy steel pipe has been studied so far and the normalizing heat treatment has the effect of changing the original API steel pipe micro structures with the help of ferrite aggregates since in a typical optical micro structure, the API steel pipe metal becomes tougher after the normalizing heat treatment even though the API steel pipe metal is imposed with its significantly lower thermal cycles when compared with the other steel pipe thermal cycles. According to scientific research results, a coarser ferrite will be generated when it is compared to the micro structure rich in ferrite and the grain size of API steel pipe in the corresponding ASTM number will have fewer normalized ferrite. It can be observed that the grain size of API steel pipe is kept relatively constant for all metals including alloy steel. SEM is widely used to identify how to repair alloy steel pipe which can be observed by optical microscopy after the metal normalization process at the grain boundary even for the low alloy metals.

As it turns out, the API steel pipe aggregate consists of such constituents as retained austenite in the normalized conditions which experience a significant drop in hardness even though the low alloyed weld metals hardness remains almost with the same, which can be attributed to the solid solution of API steel pipe that is capable of strengthening the addition of alloying elements and the formation of constituents in the API steel pipe metals. What is more, the mechanical properties for the API steel pipe metals such as the yield and tensile strength tend to increase and the results are consistent with the degree of alloying addition in the API steel pipe metals. Such a result can be measured by the carbon equivalent values as well as the associated solid solution API steel pipe strengthening so that low alloyed API steel pipe metals tend to have a higher content of fine ferrite marked by a high dislocation density and grain boundary.

• Prev:How to Obtain Black Steel Pipe Coatings
• Next:The Welded Steel Pipe Scanning Electron Microscopy