A. AMRI, O. BENLENDA, F. SABIR2 , L. ZERROUK, A. IBNLFASSI, E. SAAD
Hastelloy C2000 is a nickel-base superalloy. With the addition of copper to nickel-chromium-molybdenum system, it is resistant to a wide range of corrosive chemicals as well as the combination of molybdenum and copper creates an excellent corrosion resistance to reducing media, while the high content of the chrome provides a good oxidation resistance. Its structure is face-centered cubic. The value of our work is to study the stability of the Hastelloy C2000 on its microstructure and mechanical properties and this by a heat treatment at four temperatures: 700 °C, 800 °C, 900 °C and 1000 °C with a prolonged maintenance at each temperature for three hours. The monitoring of these two aspects is performed using the following experimentals techniques: optical microscopy and hardness measurement. After heat treatment, the pictures obtained by optical microscopy revealed the presence of different morphologies of carbides, joints and inside the grains, also we remark the appearance of the discontinuous transformations and the coalescence phenomenon of grain to form a larger area of precipitation. For hardness in the over-aging, it attains a final value of 47 for the four samples treated at 700 °C, 800°C, 900 °C and 1000 °C.
Hastelloy C2000, Heat treatment, hardness, optical microscopy.
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