Metal dusting nickel-based

C. M. Chun, G. Bhargava and T. A. Ramanarayanan, Metal Dusting Corrosion of Nickel Based Alloys,/. Electrochem. Soc., 154 C231-C240(2007). 

NICKEL AMMONIUM SULFATE or NICKEL AMMONIUM SULFATE HEXAHYDRATE (15699-18-0) Ni(NH4)2(S04)2 6H20 A weak oxidizer. Aqueous solution is acidic. Reacts violently with carbon dust, potassiiun, finely divided aluminum, magnesium. Incompatible with bases, strong acids seleniiun, sulfur carbon dust nickel nitrate potassiiun, sulfur, wood, organics, and other combustibles. Combustion releases highly toxic fumes of metallic nickel, sulfur oxide, and nitrogen oxide. 

J. K1 wer, H.J. Grabke, E.M. Mtlller-Lorenz, and D.C. Agarwal, Metal Dusting and Carburization Resistance of Nickel-base Alloys , CORROSION/97, paper no. 0139, (Houston, TX NACE, 1997). 

B.A. Baker, G.D. Smith, VW. Hartmann, and L.E. Shoemaker, Nickel-base Material Solutions to Metal Dusting Problems , CORROSION/2002, paper no. 2394, (Houston, TX NACE, 2002). 

Y. Nishiyama, N. Otsuka, T. Kudo, and O. Miyahara, Metal Dusting of Nickel-Base Alloys in Simulated Syngas Mixtures , CORROSION/2003, paperno. 3471, (Houston, TX NACE, 2003). 

Chun C M, Bhargava G, Ramanarayanan T A, Metal dusting corrosion of nickel based alloys , J. Electrochem. Soc., 2007 154 C231-C240... 

It is good practice to keep concentrations of airborne nickel in any chemical form as low as possible and certainly below the relevant standard. Local exhaust ventilation is the preferred method, particularly for powders, but personal respirator protection may be employed where necessary. In the United States, the Occupational Safety and Health Administration (OSHA) personal exposure limit (PEL) for all forms of nickel except nickel carbonyl is 1 mg/m. The ACGIH TLVs are respectively 1 mg/m for Ni metal, insoluble compounds, and fume and dust from nickel sulfide roasting, and 0.1 mg/m for soluble nickel compounds. The ACGIH is considering whether to lower the TLVs for all forms of nickel to 0.05 mg/m, based on nonmalignant respiratory effects in experimental animals. 

Braid surfaces at the failure point and a spot away from that area were analyzed. The external and internal surfaces of the braid at the failure area were mildly discolored because of oxidization, similar to the effect of overheating a metallic object. Optical microscopy and scanning electron microscopy showed no disturbance to the weave pattern, no deformation of metal wires, and no surface defects, based on the comparison of defective and normal areas. Energy dispersive x-ray (EDX) showed similar concentrations of iron (Fe), nickel (Ni), chromium (Cr), and molybdenum (Mo) in both areas, indicating stainless steel. A small amount of silicon (Si) was detected that was attributable to environmental contamination such as dust and dirt. 

---