347H

Material 347H is designed for welding high-carbon 18/8 type stainless steels, specifically titanium-stabilized and niobium-stabilized steels such as 321H and 347H. Its main applications include
catalytic crackers (known as cat crackers), cyclones, transfer lines, furnace components, steam piping, headers for superheaters, and various components of gas and steam turbines. These are commonly used in petrochemical plants, chemical processes, and power generation industries. It is important to note that alloy 16.8.2 has been developed as a more ductile alternative to 347H consumables, to mitigate problems in the Heat Affected Zone (HAZ) in service, particularly in 347H base materials with thicknesses exceeding 12 mm. Therefore, when welding thicker sections of 321H/347H, 16.8.2 consumables are preferred. For welding 321/347 intended for general applications requiring corrosion resistance up to approximately 400 °C, the use of 347 or 308L consumables is recommended. For cryogenic applications requiring a Charpy lateral expansion greater than 0.38 mm at –196 °C, it is recommended to use an unstabilized, low-carbon filler metal with controlled ferrite. No preheating or Post-Weld Heat Treatments (PWHT) are required, while the maximum interpass temperature is set at 250 °C.

Controlled, high carbon Nb stabilized stainless steel for elevated temperature service.

Austenite with 2-9FN, typically 4FN (solid wire typically 8FN).

• EN W.Nr.: 1.4941 (X6CrNiTiB18-10), 1.4961 (X8CrNiNb16-13), 1.4878 (X8CrNiTi18-10)
• ASTM: 321H, 347H
• UNS: S32109, S34709