Active Member
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[China]
Address: Room 1703, 17th Floor, Building 5, Jinyin Modern City, Guangdian South Road, Jinshui District, Zhengzhou City, Henan Province, China.
Contact name:Vicky
Zhengzhou Huitong Pipeline Equipment Co.,Ltd. |
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1.Difference between SMLS pipe fittings and welded pipe fittings
In general, the quality of seamless stainless steel pipe fittings is better than that of seamless stainless steel pipe fittings, because the seamless stainless steel pipe fittings are made of the accurate cold-rolled sheet that has passed the inspection, so any defect is limited to the welding position. Seamless tube is made of stainless steel by punching, which leads to many tears in the tube wall formed by extrusion. The eddy current test shows that the defective rate of stainless steel tube with seam is usually lower than that of seamless stainless steel tube. Using ultrasonic testing, the background noise of seamless stainless steel pipe is so large that it is difficult to find its defects. However, the background noise of stainless steel pipe with seam is very low, so it is easy to find the defect.
2.About Stainless steel 304:
Cr
| Ni
| C
| Mn
| Si
| P
| S
| Fe
| |
MIN
| 18.0
| 8.0
| 0.04
| –
| –
| –
| –
| –
|
MAX
| 20.0
| 10.5
| 0.10
| 2.0
| 0.75
| 0.04
| 0.03
| Balance
|
Minimum
| Typical
| |
Ultimate Tensile Strength, ksi
| 75
| 90
|
0.2% Yield Strength, ksi
| 30
| 35
|
Elongation, %
| 40
| 60
|
Temperature, °F
| 200
| 400
| 600
| 800
| 1000
| 1200
| 1400
| 1500
|
stress, ksi
| 20.0
| 18.3
| 16.6
| 15.2
| 14.0
| 6.1
| 2.3
| 1.4
|
4.Seamless elbow processing technology:
Seamless elbow: elbow is a kind of pipe fitting used for pipe turning. Of all the pipe fittings used in the pipeline system, the proportion is the largest, about 80%. Generally, different forming processes are selected for elbows with different materials or wall thicknesses. The forming process of seamless elbow commonly used in the manufacturer includes hot pushing, stamping, extrusion, etc. The hot push elbow forming process is a process in which a special elbow pushing machine, a core die and a heating device are used to make the blank sheathed on the die move forward under the push of the pushing machine and be heated, enlarged and bent during the movement. The deformation characteristic of the hot push elbow is to determine the diameter of the tube blank according to the law that the volume before and after the plastic deformation of the metal material is constant. The diameter of the tube blank used is smaller than the diameter of the elbow. The deformation process of the blank is controlled by the core die, so that the metal compressed at the inner arc flows and compensates to other parts thinned due to the expansion, so as to obtain the elbow with uniform wall thickness.
