Abstract:
Welded parts are generally more susceptible to corrosion than other, especially in equipments in constant contact with corrosive products. In general, in tubes, weld filet are in the longitudinal direction. This minimizes the risk of corrosion problem because the seam is located on top of the pipe where practically there is no contact with the liquid. These problems become more important in oil, because any leaks may contaminate the environment. IPT and Petrobras performed a study to evaluate whether there is preferential corrosion in tubes with helical weld in contact with gasoline, fuel oil, gasoleo (heavy fraction of oil between 270 ºC and 550 ºC), gas and ethanol with original water content, with addition of water and with corrosion inhibitor. Specimens were tested fully immersed and exposed to the vapor phase for 30 days. For petrol, oil, gas and ethanol, the temperature was 35 degrees Celsius and for fuel oil and gas oil, the temperature was 80 degrees Celsius. As it was expected, in presence of water, the products were more corrosive and corrosion inhibitors were effective to reduce the intensity of the corrosion. However, there was no preferential corrosion in the weld region, in the matrix or weld interface in any of the conditions studied.
Reference:
ALMEIDA, Neusvaldo Lira de; BONFIM, André Luis C.; MELO, Jussara; ALMEIDA, Márcio Bispo de. Estudo sobre corrosão preferencial em tubos com solda helicoidal. In: CONGRESSO INTERNACIONAL DE CORROSÃO, INTERCORR, 2014, Fortaleza. Anais… Rio de Janeiro: ABRACO, 2014. 13 p.
Logar na BiblioInfo Bibioteca-DAIT/IPT para acessar o texto em PDF. Documento está protegido com senha, solicite ao Atendimento/Biblioteca-DAIT/IPT:
escriba.ipt.br/pdf_restrito/172339.pdf
Welded parts are generally more susceptible to corrosion than other, especially in equipments in constant contact with corrosive products. In general, in tubes, weld filet are in the longitudinal direction. This minimizes the risk of corrosion problem because the seam is located on top of the pipe where practically there is no contact with the liquid. These problems become more important in oil, because any leaks may contaminate the environment. IPT and Petrobras performed a study to evaluate whether there is preferential corrosion in tubes with helical weld in contact with gasoline, fuel oil, gasoleo (heavy fraction of oil between 270 ºC and 550 ºC), gas and ethanol with original water content, with addition of water and with corrosion inhibitor. Specimens were tested fully immersed and exposed to the vapor phase for 30 days. For petrol, oil, gas and ethanol, the temperature was 35 degrees Celsius and for fuel oil and gas oil, the temperature was 80 degrees Celsius. As it was expected, in presence of water, the products were more corrosive and corrosion inhibitors were effective to reduce the intensity of the corrosion. However, there was no preferential corrosion in the weld region, in the matrix or weld interface in any of the conditions studied.
Reference:
ALMEIDA, Neusvaldo Lira de; BONFIM, André Luis C.; MELO, Jussara; ALMEIDA, Márcio Bispo de. Estudo sobre corrosão preferencial em tubos com solda helicoidal. In: CONGRESSO INTERNACIONAL DE CORROSÃO, INTERCORR, 2014, Fortaleza. Anais… Rio de Janeiro: ABRACO, 2014. 13 p.
Logar na BiblioInfo Bibioteca-DAIT/IPT para acessar o texto em PDF. Documento está protegido com senha, solicite ao Atendimento/Biblioteca-DAIT/IPT:
escriba.ipt.br/pdf_restrito/172339.pdf
