18-37 (HT-HU)

This material has been developed for welding fully austenitic, heat-resistant, high-alloy steels, commonly known as 17/38 or 38/17. The alloys in this category are typically produced in the form of castings containing around 0.4% carbon or as wrought materials with a carbon content of about 0.08%. This filler material matches the composition of the castings, but field experience has shown its compatibility with wrought alloys as well, achieving greater ductility of the weld metal by using a nickel-based filler. The high nickel content, combined with low thermal expansion, gives the deposit excellent resistance to thermal shock. The alloy is also highly resistant to carburization and oxidation, but is not suitable for use in sulfur-rich environments. These alloys maintain good mechanical properties up to 1050-1100 °C. Typical applications include trays and containers for heat treatments, retorts, furnace rollers, molds, furnace plates, radiant tubes, fittings, and manifolds for furnaces used in the heat treatment industries and in high-temperature process plants.

0.45%C-17%Cr-38%Ni high carbon austenitic heat resisting steel often called 18/37 or 37/18 alloy.

AW microstructure consists of austenite with eutectic and secondary carbides. Fully austenitic but with an apparent ferrite of up to 5FN.

• EN W.Nr.: 1.4865 (GX40NiCrSi38-18)
• ASTM: A297 HT & HU, A351 HT30
• PROPRIETARY: Paralloy H38, H40, H33, H35 (Doncasters Paralloy), Cronite HR5, HR17, HR31 (Cronite), Lloyds T50 (LBA), Thermalloy T50, T58 (Duraloy), RA330-HC (Rolled Alloys), Incoloy® DS, 330 (Special Metals)