Hastelloy C alloys are widely used in chemical and nuclear industries in corrosive environments. The predominant alloying elements of these nickel-based alloys are typically chromium and molybdenum, although other elements are added. Plasma nitriding is an efficient surface treatment to increase wear resistance. The objective of this work was to evaluate the influence of nitriding treatment on the wear and corrosion properties of the Hastelloy CW2M super-alloy. Hastelloy CW2M was plasma nitrided using the dc method with the following conditions: a gas mixture of 80 vol. % H2 and 20 vol. % N2, a pressure of 500 Pa, temperature of 450 and 500 °C during 5 h. As-cast and plasma treated samples were analyzed using scanning electron microscopy, wear and corrosion tests. An EDS line scan performed on the samples cross- section indicates that Cr and Mo content are the largest on the layer, with decreasing amounts of Ni and with stable amounts of Fe. Plasma nitriding of Hastelloy CW2M produced a homogeneous layer with high hardness. X-ray diffraction revealed a γ (fcc) phase for the un-nitrided CW2M. The nitriding performed at 450 °C yielded chromium and molybdenum nitride peaks and an expanded phase. At 500 °C, an increase on the chromium and molybdenum nitride peaks was observed. The wear of samples nitrided at 450 and 500 °C were almost 10 times lower than the substrate's wear, which indicates a great improvement on the tribological properties. The corrosion parameters showed that although the corrosion potential goes toward positive potentials, by increasing nitriding temperature, the corrosion current moves in the opposite direction. Nitriding at 450 °C promoted good corrosion protection with more positive open circuit and corrosion potentials.
Author Information
Casteletti, Luiz, Carlos
Dept. of Materials, Aeronautical and Automotive Engineering, São Carlos School of Engineering, Univ. of São Paulo, São Carlos, SP, BR
Fernandes, Frederico, Augusto Pires
Dept. of Materials, Aeronautical and Automotive Engineering, São Carlos School of Engineering, Univ. of São Paulo, São Carlos, SP, BR
Heck, Stênio, Cristaldo
Dept. of Materials, Aeronautical and Automotive Engineering, São Carlos School of Engineering, Univ. of São Paulo, São Carlos, SP, BR
Picon, Carlos, Alberto
Dept. of Physics and Chemistry, Engineering School of Ilha Solteira, Ilha Solteira, SP, BR
Totten, George, Edward
Dept. of Mechanical and Materials Engineering, Portland State Univ., Portland, OR, US
Domestic orders are delivered via United Parcel Service (UPS) or United States Postal Service (USPS). Transit
times average 3 to 5 business days. Please be aware that UPS will not deliver packages to Post Office Boxes.
International orders are delivered via courier post services which can be either a postal service, courier
service, or a combination of both. Standard Service is untraceable. Please allow 4-7 weeks for delivery.
Please be aware that carriers will not deliver packages to Post Office Boxes. Because of the variability of
customs processes and procedures in different countries, ASTM International cannot guarantee transit times to
international destinations. Customs duty and taxes are the responsibility of the consignee.
Shipping & Handling charges follow the rate schedule, below:
Order Total
Shipping & Handling Fee (US Domestic)
Up to $50.00
$18.72
$50.01 to $100.00
$20.80
$100.01 to $150.00
$29.52
$150.01 to $250.00
$39.09
$250.01 to $500.00
$56.25
$500.01 to $750.00
$76.42
$750.01 to $1000.00
$93.15
$1000.01 to $1500.00
$121.27
$1500.01 to $2500.00
$158.38
$2500.01 to $4999.00
$209.04
$5000.00 to higher
FREE
Order Total
Shipping & Handling Fee (International)
Up to $50.00
$68.72
$50.01 to $100.00
$70.80
$100.01 to $150.00
$79.52
$150.01 to $250.00
$89.09
$250.01 to $500.00
$106.25
$500.01 to $750.00
$126.42
$750.01 to $1000.00
$143.15
$1000.01 to $1500.00
$171.27
$1500.01 to $2500.00
$208.38
$2500.01 to $4999.00
$259.04
$5000.00 to higher
FREE
Shipping and Handling charges are approximate. Additional charges may be incurred if your order requires multiple shipments. This does not apply to complete sets and sections.