Along with utilizing high strength materials, the pressure vessels can be made from thinner walls are utilized thus being more economical, nevertheless for most, the desirable materials tend to go ...through environmental deterioration. In case of LPG tanks, in 1965 high tensile steel (HT70) was first used to be followed by spherical tanks which were made of HT80. in these facilities, as countermeasure to crack formation at around weld joints it was necessary to keep weld portion hardness below Hv300 and tank containment of H sub 2S density below 50 ppm. Corrosion in liquid ammonia tanks have been deemed to be due to combination of moisture, air and CO sub 2 in the tank. The stress corrosion cracks are common in chemical facilities' towers, tanks and various heat exchangers made of stainless steel. According to a poll taken in 1965 by Association of Chemical Industries in Japan, majority of cracks in austenite stainless pipes were occurred in the vertical heat exchangers. In 1970s the stress corrosion resistant and 2-phase stainless steel (5Cr-5Ni) became available and standardized through JIS. When heated to 300~600DGC and 750~1050DGC, the impact values (kgf-m/cm sup 2) of this steel rapidly drops as shown in the diagram. Reliability enhancement of stainless steels, through adding Ti, Nb, Cb and other metals is discussed along with reviewing C and Nb effects on Carpenter 20 microcrack formation. Additionally, the organic materials like glass-carbon reinforced fiber (FRP) composites and ceramics are introduced with tables and performance behavior such as relationship between corrosion and water quality in SGP joints.
Along with utilizing high strength materials, the pressure vessels can be made from thinner walls are utilized thus being more economical, nevertheless for most, the desirable materials tend to go ...through environmental deterioration. In case of LPG tanks, in 1965 high tensile steel (HT70) was first used to be followed by spherical tanks which were made of HT80. in these facilities, as countermeasure to crack formation at around weld joints it was necessary to keep weld portion hardness below Hv300 and tank containment of H sub 2 S density below 50 ppm. Corrosion in liquid ammonia tanks have been deemed to be due to combination of moisture, air and CO sub 2 in the tank. The stress corrosion cracks are common in chemical facilities' towers, tanks and various heat exchangers made of stainless steel. According to a poll taken in 1965 by Association of Chemical Industries in Japan, majority of cracks in austenite stainless pipes were occurred in the vertical heat exchangers. In 1970s the stress corrosion resistant and 2-phase stainless steel (5Cr-5Ni) became available and standardized through JIS. When heated to 300approx600 deg C and 750approx1050 deg C, the impact values (kgf-m/cm exp 2 ) of this steel rapidly drops as shown in the diagram. Reliability enhancement of stainless steels, through adding Ti, Nb, Cb and other metals is discussed along with reviewing C and Nb effects on Carpenter 20 microcrack formation. Additionally, the organic materials like glass-carbon reinforced fiber (FRP) composites and ceramics are introduced with tables and performance behavior such as relationship between corrosion and water quality in SGP joints.
