22 research outputs found
Microstructural characterization and mechanical behavior during recrystallization annealing of Nb-stabilized type ASTM 430 and Nb-Ti-stabilized ASTM 439 ferritic stainless steels
InfluĂȘncia dos estrativos na resistĂȘncias ao apodrecimento de seis espĂ©cies de madeira
Microstructure, Texture and Microhardness Evolution during Annealing Heat Treatment and Mechanical Behavior of the Niobium-Stabilized Ferritic Stainless Steel ASTM 430 and Niobium-Titanium-Stabilized Ferritic Stainless Steel ASTM 439: a Comparative Study
Comparative Study of Microstructure, Texture, and Formability Between 11CrTi and 11CrTi+Nb ASTM 409 Ferritic Stainless Steel
FamĂlias escravas em Minas Gerais nos inventĂĄrios e registros de casamento o caso de SĂŁo JosĂ© do Rio das Mortes, 1743-1850
O império dos mil anos e a arte do "tempo barroco": a åguia bicéfala como emblema da Cristandade
FAILURE ANALYSIS IN TUBING OF AIR PREHEATER OF BOILER FROM A SUGARCANE MILL
The increased demand for energy from sugarcane bagasse has made the sugar and alcohol mills search alternatives
to reduce maintenance of the boilers, releasing more time to the production. The stainless steel use has become one
of the main tools for such reduction. However, specification errors can lead to premature failures. This work reports
the factors that led tubes of AISI 409 stainless steel fail after half season when applied in a air preheater of boiler from a
sugarcane mill. In such application, the AISI 304 lasts about 15 seasons and the carbon steel about 3. A tube sent by the
sugar mill was characterized by wet chemical analysis, optical microscopy and EDS. Results indicated chloride formation
on the internal walls of the tube, which combined with the environment, accelerated the corrosion process. The carbon
steel showed high lifetime due to a 70% higher thickness. Due to the work condictions is recommended the use of
stainless steels with higher corrosion resistance, such as the traditional AISI 304 or the ferritic AISI 444, the last presents
better thermal exchange