Harald Pihl

INCOLOY® alloy DS (W. Nr. 1.4862), first developed for woven wire furnace conveyor belts, is now widely used for a range of heat-treatment applications where its strength and corrosion resistance at high temperatures enable its use in light section. Alloys for use in high-temperature processes must be able to withstand exposure to hot combustion gases and operating atmospheres for a considerable period of time without the loss of effective section that can be caused by corrosion. INCOLOY alloy DS, in common with other Special Metals Corporation heat-resisting alloys, develops a tightly adherent oxide film that protects its surface against corrosion processes. It is also resistant to ‘green rot’ which can occur in nickel-chromium alloys when atmospheres vary between reducing and oxidizing, and in some cases where the reducing atmosphere is of a carburizing nature. In these conditions chromium carbide can form along the grain boundaries and preferential oxidation of the depleted chromium matrix follows, a form distinct from ordinary oxidation which produces a passive oxide film. INCOLOY alloy DS is also resistant to ‘sigma’ phase, a hard, brittle, complex intermetallic compound, basically iron-chromium, which precipitates in the 600-900°C range from structures that are either ferritic, mixed ferrite and austenite, or marginally austenitic. Nickel, an austenite former, suppresses the tendency to ‘sigma’ phase formation and INCOLOY alloy DS, with a nominal 37% nickel content, may be heated indefinitely within the 600-900°C range without fear of ‘sigma’ phase embrittlement. Thus, the corrosion resistance and strength of INCOLOY alloy DS account for its use in a wide variety of high temperature process equipment ranging from furnace retorts and heat treatment jigs to components used in domestic appliances.

AWS A5.11 ENiCrMo-3, UNS W86112, W.Nr. 2.4621

AWS A5.11 ENiCrCoMo-1, UNS W86117, W.Nr. 2.4628

AWS A5.11 ENi-1, UNS W82141, W.Nr. 2.4156

UNS N06600, W.Nr. 2.4816

AWS A5.14 ERNiCrFe-11, UNS N06601, W.Nr. 2.4626

AWS A5.14 ERNiCrCoMo-1, UNS N06617, W.Nr. 2.4627

UNS N06625, W.Nr. 2.4856

INCONEL® 625 LCF is a variant of INCONEL® 625. LCF stands for Low Cycle Fatigue. This means that the alloy has improved cycle fatigue properties and better thermal fatigue resistance. In other aspects such as chemical composition and other mechanical properties the alloy is similar to INCONEL® 625. The alloy is e.g. used for bellows, aircraft exhausts and expansion joints.

INCONEL® alloy 686 (UNS N06686/W.Nr. 2.4606) is a single-phase, austenitic Ni-Cr-Mo-W alloy offering outstanding corrosion-resistance in a range of severe environments.