Selection of raw materials of metal gasket
Selection of gasket material mainly depends on the followingthree factors: temperature and pressure medium
1 carbon steel:
The recommended maximum working temperature less than 538 ℃, especially when the medium with oxidation time. High quality thin carbon steel plate is not suitable for makinginorganic acid, neutral or acidic salt solution of equipment, ifcarbon steel under stress, for hot working conditions of equipment accident rate is very high. Carbon steel gasket is usually used for high concentration of acid and alkali solution.Brinell hardness of about 120.
2.304 stainless steel
18-8 (18-20%, 8-10%, Cr, Ni) recommended maximum working temperature does not exceed 760 ℃. At thetemperature of -196~538 ℃ range, prone to stress corrosionand intergranular corrosion. Brinell hardness of 160.
3 304L stainless steel
The carbon content of not more than 0. 3%. The recommended maximum working temperature does not exceed 760 ℃. Corrosion resistance is similar to the 304stainless steel. Low carbon content reduces carbon from thelattice of precipitation, grain boundary corrosion resistantperformance is higher than that of 304 stainless steel. Brinell hardness of about 140.
4.316 stainless steel
18-12 (chromium 18% nickel, 12%), an increase of about 2%Mo in 304 stainless steel, when the temperature increase the strength and corrosion resistance performance. When the temperature increases than other ordinary stainless steel hashigher creep resistance properties. The recommendedmaximum working temperature does not exceed 760 ℃.Brinell hardness of about 160.
5 316L stainless steel
The recommended maximum continuous operatingtemperature does not exceed 760 ℃ ~815 ℃. The carboncontent of no more than than 316 stainless steel has excellent resistance to stress and grain boundary corrosion.Brinell hardness of about 140.
45% iron, nickel, chromium and 24% 20% small amounts of molybdenum and copper. The recommended maximum working temperature does not exceed 760 ℃ ~815 ℃.Particularly suitable for the manufacture of sulphuric acid corrosion resistant equipment, Brinell hardness of about 160.
Aluminum (content of not less than 99%). Aluminum has goodcorrosion resistance and processing properties, applicable to the manufacture of double clip gasket. Brinell hardness of about 35. The recommended maximum continuous operatingtemperature does not exceed 426 ℃.
Copper composition close to the pure copper, it contains trace amounts of silver to increase its continuous working temperature. The recommended maximum continuous operating temperature does not exceed 260 ℃. Brinell hardness of about 80.
(copper 66%, zinc 34%), in most conditions, good corrosion resistance, but not adapt to acetic acid, ammonia, salt and acetylene. The recommended maximum continuous operatingtemperature does not exceed 260 ℃. Brinell hardness of about 58.
10 Hastelloy B-2
(26-30% molybdenum, nickel and iron in 62% 4-6%). The recommended maximum working temperature does not exceed 1093 ℃. With the heat concentration hydrochloric acid corrosion performance. Also has the properties ofcorrosion resistance, sulfuric acid, and phosphoric acid in wethydrogen chloride gas reducing salt solution corrosion ofexcellent. With high strength in high temperature conditions.Brinell hardness of about 230.
11 Hastelloy C-276
16-18%, 13-17.5%, 3.7-5.3% chromium molybdenumtungsten, 4.5-7% iron, nickel) for the rest. The recommendedmaximum working temperature does not exceed 1093 ℃.Excellent corrosion resistance. The various attempts of coldor nitrate concentration reached 70% boiling nitric acid has excellent corrosion resistance, good resistance tohydrochloric acid and sulfuric acid corrosion resistance andexcellent resistance to stress corrosion cracking. Brinell hardness of about 210.
12 Inconel 600
Nickel base alloys (77%, 15% and 7% nickel chromium iron).The recommended maximum working temperature does not exceed 1093 ℃. With high strength at high temperature, is usually used to solve stress corrosion problems of equipment.Under the condition of low temperature, has the sameexcellent machining performance. Brinell hardness of about 150.
13 Monel 400
(Cu 30%, Ni recommended maximum continuous operatingtemperature does not exceed 815 ℃. In addition to strong oxidizing acid, with excellent corrosion resistance to mostacids and bases. In hydrofluoric acid, mercuric chloride,mercury medium susceptible to stress corrosion cracking,therefore, not suitable for the medium. Is widely used in the manufacture of hydrofluoric acid equipment. Brinell hardnessof about 120.
The recommended maximum working temperature does not exceed 1093 ℃. Under the condition of high temperature,has excellent corrosion resistance. As everyone knows the erosion resistance of chloride ion, in a wide range oftemperature and concentration of nitric acid corrosion resistance, has excellent. Little titanium in most alkali solution,suitable for the oxidation conditions. Brinell hardness of about 216.