AWS Class E309LMo-16 Coated Electrodes – Composition, Properties, and Uses
AWS Class E309LMo-16 coated electrodes are a type of stainless steel welding electrode primarily used in welding stainless steels that contain molybdenum. These electrodes are known for their excellent weldability and corrosion resistance properties, making them popular in the construction, oil and gas, and chemical industries. This blog post will explore the composition, physical and mechanical properties, heat treatment, and corrosion resistance of AWS Class E309LMo-16 coated electrodes. By the end of this post, you will clearly understand why this type of electrode is so popular and how it can be used in various applications.
What are AWS Class E309LMo-16 Coated Electrodes?
AWS Class E309LMo-16 Coated Electrodes is a type of welding wire used in shielded metal arc welding (SMAW) or stick welding. This particular coated electrode class provides excellent mechanical properties and resistance to acidic environments. It comprises an iron base alloy coated with a layer containing 16-18% chromium for increased corrosion protection, hence its designation “309”; the additional “LMo” stands for low molybdenum content and excess ferrite control. The low hydrogen coating enhances impact toughness and flexibility, providing excellent slag detachability and superior weld bead appearance. Additionally, the series has great crack resistance and acts as an effective choice when joining base metals that require higher tensile strength than what conventional consumables can provide.
E309LMo-16 Welding Electrodes Composition
AWS Class E309LMo-16 electrodes contain a combination of elements that make them an excellent choice for welding applications. The primary composition of these electrodes includes Chromium (Cr), Nickel (Ni), Molybdenum (Mo), and Carbon (C). Other elements, such as Silicon (Si) and Manganese (Mn), may also be in smaller amounts.
AWS Spec |
Weld Metal Analysis (%) |
|
Carbon (C) |
0.04 | 0.03 |
Chromium (Cr) |
22.0-25.0 | 23.5 |
Copper (Cu) |
0.75 | 0.06 |
Manganese (Mn) |
0.5-2.5 | 1.10 |
Molybdenum (Mo) |
2.0-3.0 | 2.60 |
Nickel (Ni) |
12.0-14.0 | 13.8 |
Phosphorus (P) |
0.04 | 0.003 |
Silicon (Si) |
1.00 | 0.64 |
E309LMo-16 Coated Electrodes Physical Properties
AWS Class E309LMo-16 welding electrodes have a melting point of around 1370°C (2498°F) and a low thermal expansion coefficient of around 11.2 x 10^-6m/m°C. These electrodes have a specific gravity of 7.8, making them relatively heavy. They are also known for their excellent corrosion resistance properties and are resistant to various corrosive media types, including seawater, acids, and alkalis.
E309LMo-16 Welding Electrodes Mechanical Properties
AWS Class E309LMo-16 welding wire have excellent mechanical properties, making them an ideal choice for a wide range of welding applications. These electrodes have a Tensile Strength of around 625 MPa (90,000 psi) and a Yield Strength of around 430 MPa (62,000 psi). These electrodes can withstand significant stress and pressure, making them suitable for high-stress environments.
E309LMo-16 Coated Electrode Trade Name
Class | UNS | Oxford Alloys | BOHLER |
E309LMo-16 | W30923 | Alloy 309LMo-16 | BOHLER FOX CN 23/12 MO – A 309LMO-17 |
E309LMo-16 Welding Electrodes Parameters
Diameter |
Type of Current |
Amperage Range |
Voltage Range |
|
Flat | Out of Position | |||
3/32” | DCEP or AC | 70-90 | 65-80 | 20-23 |
1/8” | DCEP or AC |
80-110 |
75-95 | 21-24 |
5/32” | DCEP or AC |
120-160 |
100-120 | 22-25 |
3/16” | DCEP or AC |
170-190 |
Not recommended | 23-26 |
E309LMo-16 Coated Electrodes Uses
AWS Class E309LMo-16 welding alloy are primarily used in constructing offshore oil rigs, chemical plants, and other applications that require resistance to harsh environments. These electrodes can also be used to weld stainless steel that contains molybdenum, such as 316L stainless steel.
E309LMo-16 Coated Electrodes Heat Treatment
AWS Class E309LMo-16 filler wire can be heat-treated to improve their mechanical properties. Heat treatment involves heating the electrode to a specific temperature and cooling it down slowly. This process can enhance the strength and ductility of the electrode and make it more resistant to stress and pressure.
E309LMo-16 Welding Electrodes Corrosion Resistant
AWS Class E309LMo-16 filler metal are known for their excellent corrosion resistance properties. These electrodes contain elements that make them resistant to various corrosive media types, including seawater, acids, and alkalis. This makes them an ideal choice for welding applications that require resistance to harsh environments.
Conclusion
AWS Class E309LMo-16 coated electrodes are an ideal choice for welding applications that require resistance to harsh environments. These electrodes contain elements that give them excellent weldability and corrosion resistance properties, making them a popular choice in the construction, oil and gas, and chemical industries. By understanding the composition, physical and mechanical properties, uses, heat treatment, and corrosion resistance of these electrodes, one can choose the right electrode type for their specific welding application. Whether welding stainless steel containing molybdenum or working in a harsh environment, AWS Class E309LMo-16 coated electrodes will deliver the needed performance.
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