Yuhong Group Co.,Ltd
Yuhong Holding Group Co.,LTD
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What is a stainless steel elbow?
Stainless steel pipe elbow (sometimes also refereed as bends) is a key part in a pressure piping system used to change the fluid flow direction. It is used to connect two pipes with same or different nominal diameters, and to make the pipe and thus the fluid direction turn to a certain direction of 45 degree or 90 degree.
What is grade SS904L/UNS N08904?
Grade SS904L stainless steel is a non-stabilized austenitic stainless steel with low carbon content. This high alloy stainless steel is added with copper to improve its resistance to strong reducing acids, such as sulphuric acid. The steel is also resistant to stress corrosion cracking and crevice corrosion. Grade SS904L is non-magnetic, and offers excellent formability, toughness and weldability. Grade SS904L contains high amounts of expensive ingredients, such as molybdenum and nickel. Today, most of the applications that employ grade 904L are replaced by low-cost duplex stainless steel 2205.
Grade 904L stainless steels have excellent resistance to warm seawater and chloride attack. The high resistance of grade 904L against stress corrosion cracking is due to the presence of high amounts of nickel in its composition. Moreover, the addition of copper to these grades develops resistance to sulphuric acid and other reducing agents in both aggressive and mild conditions. The corrosion resistance of grade 904L is intermediate between super austenitic grades, with 6% molybdenum content, and standard 316L austenitic grades. Grade 904L is less resistant to nitric acid than grades 304L and 310L, which are free of molybdenum. This steel grade needs to be solution treated following cold working, to achieve maximum stress corrosion cracking resistance under critical environments.
SS904L Mechanical Properties
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| 7.95 g/cm3 | 1350 °C (2460 °F) | Psi – 71000 , MPa – 490 | Psi – 32000 , MPa – 220 | 35 % |
SS904L Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | Cu |
| SS 904L | 0.020 max | 2.00 max | 1.00 max | 0.040 max | 0.030 max | 19.00 – 23.00 | 4.00 – 5.00 max | 23.00 – 28.00 | 1.00 – 2.00 |
SS904L Equivalent Grades
| STANDARD | WERKSTOFF NR. | UNS | JIS | GOST | EN |
| SS904L | 1.4539 | NO8904 | SUS 904L | 904S13 | STS 317J5L |
WP904L Fittings Application:
