Introduction

Haynes 188 is a cobalt-based alloy  which possesses a unique combination of properties. It has excellent high  temperature strength and oxidation resistance to 2100°F (1150°C) combined  with good post-aging ductility.

Characters

Haynes 188 has average room temperature tensile  properties in the bright annealed condition of 137.2 ksi (946 MPa) ultimate  strength, 67.3 ksi (464 MPa) yield strength and 53% elongation. At 1800°F  (980°C) the alloy has ultimate and yield strengths of 35.2 ksi (243 MPa) and  19.0 ksi (131 MPa), respectively, with 59% elongation. Cryogenic temperatures  do not significantly affect the ductility of alloy 188, but strength levels are  increased markedly.

The excellent oxidation resistance of Haynes 188  results from minute additions of lanthanum, which modifies the protective  oxide scale in such a manner that the oxide becomes extremely tenacious and  retards diffusion when exposed to temperatures through 2100°F (1150°C).

Haynes 188 exhibits good ductility after prolonged  exposure at temperatures of 1200, 1400, and 1600°F (650, 760 and 870°C) for  16,000 hours.

Application

Because of its excellent strength, ductility and  oxidation resistance, Haynes 188 meets the critical high-temperature material  requirements for gas turbine applications as well as many of those in the  airframe, chemical and nuclear fields. Typical uses are as transition ducts,  combustor cans, spray bars, flame-holders and afterburner liners in jet  engines.

Equal grades

UNS R30188, GH5188(China), KCN22W(France),  Alloy188

Chemical  composition

Carbon 0.05~0.15

Manganese 1.25 max

Silicon 0.20~0.50

Phosphorus--0.02 max

Sulfur--0.015 max

Chromium 21.0~23.0

Nickel 20.0~24.0

Tungsten 13.0~15.0

Lanthanum 0.03~0.12

Boron --0.015 max

Iron --3.0 max

Cobalt Bal.

Standard

AMS 5608, AMS 5772,

Forms of product  available at A-one Alloy

Plate, sheet, strip, rod, bar,  forging. ring

Delivery

Available on request