corrosion resistance tables schweitzer pdf

This book is included in the following series: Informa UK Limited, an Informa Plc company. CD4MCu is a cast duplex SST that has been in use for many years.

8243CHAPTER 113/11/200616:59BSARAVANAN14191XML MODEL B pp. 8243CHAPTER 133/11/200617:14BSARAVANAN14193XML MODEL B pp. 109122 118 Fundamentals of Metallic Corrosion: Atmospheric and Media Corrosion of Metals 45 Scaling % weight loss 40 35 30 25 20 15 10 5 0 0 2 4 6 8 10 12 14 16 18 % Chromium 20 22 24 FIGURE 6.2 Effect of chromium content on scaling resistance at 18008F (9828C). The various stainless steel alloys can be divided into seven basic families: 1. Suspended particles of carbon and carbon compounds, metal oxides, sulfuric acid, ammonium sulfate, sodium chloride, and other salts will be found in industrial atmospheres. Equation (1.4) then becomes Vcorr Z icorr nF (1.5) The corrosion potential lies between the equilibrium potentials of the anodic and cathodic partial reactions. Moisture on the surface of the metal resulting from high humidity of the atmosphere and the chemical and physical properties of the corrosion products produces an adsorption layer of water. Corrosion Resistance Tables, Vols. In highchlorine coals, values of 0.7% are found. The alloy has the following composition: Chemical Carbon Manganese Silicon Phosphorus Sulfur Chromium Nickel Cobalt Titanium Columbium Aluminum Copper Boron Iron Weight Percent 0.05 0.50 0.30 0.015 0.015 5.50 25.0 29.0 0.80 4.80 0.50 0.50 0.01 Balance References 1. It is about three times more efcient at this than chromium. Alloy 439L is resistant to chloride stress corrosion cracking, organic acids, alkalies, and nitric acid. P. A. Schweitzer. The corrosion resistance of ductile iron is comparable to that of gray iron with one exception; under velocity conditions the resistance of ductile iron may be slightly less than that of gray iron because it does not form the same type of lm that is present in gray iron. After the corrosion resistance plateau of 18% chromium is reached, the addition of approximately 8% nickel is required to cause a transition from ferritic to austenitic. The most common contaminant is embedded or free iron particles from forming or machining tools. Stresses, either residual or applied, impact the mode of corrosion and lower the energy effect for corrosion to begin. By the addition of copper, improved resistance to general corrosion in sulfuric acid is obtained. Duplex stainless steels have been available since the 1930s. The alloy has been used for solenoid valve magnetic core components that must combat corrosion from atmospheric fresh water and corrosive environments. Dezincication can be suppressed by alloying additions of tin, aluminum, arsenic, or phosphorus. The equilibrium potential of the partial reactions is predicted by electrochemical thermodynamics. The chemical composition is shown in Table 10.1. If not thoroughly rinsed, chloride pitting, crevice corrosion, or stress corrosion cracking may occur. 8243CHAPTER 33/11/200616:56TRGANESH14183XML MODEL B pp. 3. 2004. Condition A material has been used successfully in numerous applications. It has a maximum temperature rating of 20008F (10958C) for continuous service and a maximum temperature rating of 21508F (11758C) for intermittent service. 14, 5th ed., New York: Marcel Dekker. Carbide precipitation forms in the areas to the right of the various carbon-content curves. It is these materials, when combined with moisture, that initiate corrosion. Source: From P.A. Alloy A286 has excellent resistance to sulfuric and phosphoric acids and good resistance to nitric acid and organic acids. However, the degree to which these pollutants will affect the corrosion rate will be inuenced by the other preceding factors that also have an inuence on the corrosion rate. 118 21.2.5 Liquid Metals 21.2.5.1 Aluminum . 21.2.5.2 Antimony 21.2.5.3 Bismuth 21.2.5.4 Calcium 21.2.5.5 Cesium . 21.2.5.6 Gallium 21.2.5.7 Lead 21.2.5.8 Lithium 21.2.5.9 Magnesium and Magnesium Alloys.. 21.2.5.10 Mercury .. 21.2.5.11 Potassium .. 21.2.5.12 Silver . 21.2.5.13 Sodium 21.2.5.14 Tellurium 21.2.5.15 ThoriumMagnesium 21.2.5.16 Uranium and Plutonium Alloys .. 21.2.5.17 Zinc 21.2.6 General Corrosion Data. 21.3 Corrosion Resistance of Tantalum-Based Alloys 21.3.1 TantalumTungsten Alloys . 21.3.2 TantalumMolybdenum Alloys .. 21.3.3 TantalumNiobium Alloys . 21.3.4 TantalumTitanium Alloys . 21.3.5 Other Alloys .. References . 555 556 556 556 556 556 556 556 556 557 557 557 557 557 558 558 558 558 558 561 563 566 566 567 568 568 Chapter 22 Zirconium . 22.1 Introduction .. 22.2 General Characteristics . 22.2.1 Physical Properties 22.2.2 Mechanical Properties 22.2.3 Chemical and Corrosion Properties. 22.2.3.1 Water and Steam.. 22.2.3.2 Salt Water .. 22.2.3.3 Halogen Acids 22.2.3.4 Nitric Acid 22.2.3.5 Sulfuric Acid 22.2.3.6 Phosphoric Acid .. 22.2.3.7 Other Acids.. 22.2.3.8 Alkalies 22.2.3.9 Salt Solutions .. 22.2.3.10 Organic Solutions 22.2.3.11 Gases. 22.2.3.12 Molten Salts and Metals. 571 571 573 574 574 577 580 581 582 586 588 591 594 594 594 596 597 598 8243Prelims10/11/200618:40CRCPAG14180XML MODEL B pp. In the quenched and fully tempered condition (usually below 25 HRC), SCC resistance is greatly improved, especially for CA6NM. Result H O H O H O H O H O Hydroxylated metal oxide. Type 440A has lower carbon content than type 440B or 440C and consequently exhibits a lower hardness but greater toughness. It is also common for dew to form during the early morning hours when the air temperature rises more quickly than the metal temperature. This approach was rst used during and shortly after World War II in response to nickel shortages. Custom 455 exhibits high strength with corrosion resistance better than type 410 and approaching type 430. 109122 Corrosion of Stainless Steels 121 Low concentrations of hydrogen sulde can be handled satisfactorily in low-chromium stainless steels. The inuence of oxidizers is the same as for nickel. 2.2.1.6 Dust On a weight basis in many locations, dust is the primary air contaminant. TABLE 2.3 Approximate Number of Water Monolayers on Different Metals vs. of material is removed. It is intended to compete with titanium in the handling of high-chloride environments. A more comprehensive listing will be found in Reference [1]. 8243CHAPTER 77/11/200619:53THIRAVIAGURU14187XML MODEL B pp. Have an inuence on the rate of anodic or cathodic reaction 5. Cast CB7Cu-1 was recently added to the NACE standard MR0175 for nonpressure-containing, internal valve and pressure regulator components. These alloys have better general corrosion resistance than type 304 and type 309. Almost any lack of homogeneity on the metal surface or in its environment may initiate attack by causing a differential in potentials that results in more or less localization of corrosion. CF8C (cast equivalent of 347) contains columbium to stabilize the material against chromium carbide formation. (0.787 mm) thick were exposed on both sides. 197204 204 Fundamentals of Metallic Corrosion: Atmospheric and Media Corrosion of Metals Ferralium exhibits good corrosion resistance to a variety of media, with a level of resistance to chloride pitting and SCC. P.A. 2.7.2 Weathering Steels Weathering steels are steels to which small amounts of copper, chromium, nickel, phosphorus, silicon, manganese, or various combinations thereof have been added. Type 348H stainless steel is a high-carbon version of type 348 designed to provide better high-temperature creep properties and to meet the requirements of ASME Section VIII, Table UHA-21, Footnote 8. Most show little or no shrinkage during solidication, so that pattern making is simplied compared to other alloys. CF8 castings are more expensive than CF8M and should only be specied when CF8M cannot be used. A moisture lm in contact with an atmosphere highly polluted with SOx may initially have a pH value as low as 2. However, they do perform well in molten carbonates up to 9308F (5008C). CORROSION CONTROL CD-ROM Version 2.2.1.4 Rain Rain creates even thicker layers of electrolyte on the surface than dew. In fact, the chromium depletion can be so severe as to lower the chromium content locally to below the 11% content considered to be the minimum for stainless steel. Malleable iron is only available in thin sections because rapid cooling in the mold is required to form white iron. In addition, there are many alloy castings available in compositions that are not available as wrought materials. Type 321 stainless steel can be used with improved corrosion resistance wherever type 316 is suitable, particularly in the presence of nitric acid. It is a martensitic, age-hardenable stainless steel with very good corrosion resistance and moderate strength. However, their availability is still limited in thicknesses less than approximately 0.20 in. Alloy compositions 8243CHAPTER 63/11/200617:01TRGANESH14186XML MODEL B pp. 139149 Martensitic Stainless Steel Family 145 TABLE 9.4 Chemical Composition of Type 416 Stainless Steel Chemical Carbon Manganese Phosphorus Silicon Chromium Molybdenum Iron a Weight Percent 0.15 1.25 0.060 1.00 12.0014.00 0.60a Balance May be added at manufacturers option. A signicant benet is realized with the addition of only about 2% molybdenum. Reference 1. 5. The chemical composition is as follows: Chromium Nickel Carbon NiobiumCtantalum Iron 17.0/20.0% 9.0/13.0% 0.08% 10!carbon min 1.0% max (0.1% max tantalum) Balance 8243CHAPTER 103/11/200617:05CRCPAG14190XML MODEL B pp. 8243CHAPTER 113/11/200616:59BSARAVANAN14191XML MODEL B pp. It resists a variety of oxidizing salts, but not halide salts. The chemical composition will be found in Table 13.3.

At high temperatures, 904L may be subject to stress corrosion cracking. 205220 206 Fundamentals of Metallic Corrosion: Atmospheric and Media Corrosion of Metals centered around forging difculties, but these problems have been overcome to some extent. Refer to Table 4.4 for the compatibility of Ni-Resist alloy with selected corrodents. It can be expressed as the inverse of the sum of two resistances, namely, aerodynamic resistance and surface resistance: Vd Z 1 Ra C Rs where VdZdry deposition velocity RaZaerodynamic resistance RsZsurface resistance In general, the dry deposition velocity will be the combined effect of both resistances. Ammonium hydroxide, sat. They exhibit outstanding resistance to hot alkalies, particularly caustic soda. Over this period, a protective lm or patina, darkbrown to violet in color, forms. Commercially pure nickel is a white magnetic metal very similar to copper in its other physical and mechanical properties. Equation (1.10) corresponds to a partial reduction reaction and the stoichiometric coefcients vox,i and vred,i are both positive.

137 12 Fundamentals of Metallic Corrosion: Atmospheric and Media Corrosion of Metals Several steps can be taken to prevent and/or control crevice corrosion: 1. Iron, as Fe2C or Fe3C, is required for the electron transport system, where it acts as an oxidizable/reducible central atom in cytochromes of nonheme iron-sulfur proteins. Heavily industrialized areas have reported pH values of dew in the range of 3 or lower. At worst, some slight staining may develop. Dry uorine and bromine can be handled in the same manner. It has PREN of 54.45. 11.7 Type 330 (N08330) This is a nickelchromiumiron alloy with the addition of silicon. These alloys are hardenable because of the phase transformation from bodycentered cubic to body-centered tetragonal. The composition will be found in Table 11.9.

Chromium carbides in themselves do not suffer from poor corrosion resistance. Segregation of specic elements or compounds at the grain boundary, as in aluminum alloys or nickelchromium alloys 8243CHAPTER 13/11/200616:52TRGANESH14181XML MODEL B pp. Over-aged material is subject to intergranular corrosion. Due to the presence of nickel, chromium, and molybdenum they are also susceptible to the formation of s phase. While most grades contain at least 5% ferrite and weakly attract a magnet, it is not unusual for CG8M to contain as much as 30% ferrite and strongly attract a magnet. The majority of such molecules will form hydrogen bubbles and oat away harmlessly. Even with alloying additions such as molybdenum to improve localized corrosion resistance to halogens, the workhorse 304 and 316 alloys are susceptible to chloride stress corrosion cracking (SCC). Incompatibility is shown by an X. 177195 Superaustenitic Family of Stainless Steel 187 At moderate temperatures, the general corrosion resistance of alloy 800 is similar to that of other austenitic nickelironchromium alloys. b Mn range 4.407.50. 8243CHAPTER 23/11/200616:54TRGANESH14182XML MODEL B pp. Extensive testing is required to develop a melting practice, compositional TABLE 4.2 Examples of ACI Designations Alloying Elements (%) Designation CA15 CD4MCu CF8M CF3M CN7M CW2M CZ100 HK40 Chromium, Nominal Nickel, Nominal Carbon, Maximum 12 25 19 19 21 16 0 25 6 10 10 29 68 100 20 0.15 0.04 0.08 0.03 0.07 0.02 1.0 0.40 Other Alloying Elements, Nominal Mo 3; Cu 3 Mo 2.5 Mo 2.5 Mo 2.5 Mo 1.6 8243CHAPTER 43/11/200616:57TRGANESH14184XML MODEL B pp. Addition of alloying elements to titanium affect the corrosion resistance because these elements affect the composition of the oxide lm. Excellent oxidation resistance is displayed up to 18008F (9528C). For both alloys, the higher hardness conditions are quite susceptible to SCC. Corrosion rates are expressed as a factor of time. 10.18 Type 348 (S34800) Type 348 stainless is the same as type 347 except that the tantalum content is restricted to a maximum of 0.10%. Notice in Table 1.2 that the precious metals gold and platinum are at the higher potential (more noble or cathodic) end of the series (protected end), while zinc and magnesium are at the lower potential (less noble or anodic) end. 4.2.2 Austenitic Ductile Cast Irons These alloys are commonly called ductile Ni-Resist. It has a PREN of 40. The compatibility of alloy 825 with selected corrodents is shown in Table 11.5. Informa UK Limited, an Informa Plc company. Whether or not new SO2 can be introduced into the region is dependent on the actual wind speed, type of wind ow, and shape of the sample. After 4 years immersion, for example, Cor-Ten steel showed an average corrosion rate of 2.7 mpy (69 mm/year) with a maximum pit depth of 24 mils (360 mm). 4.1.1 Gray Iron Gray iron is the most common cast iron, representing 59% of total worldwide production in 1993. Elongation in the hardened condition is typically about 2%. As a result of the chromium addition, signicant improvements in environmental resistance over that of the CTX alloys is realized. 118 16.3 NickelChromium 16.4 NickelChromiumMolybdenum . 16.5 Other Nickel-Based Alloys. References . Chapter 17 281 281 282 282 Comparative Corrosion Resistance of Stainless Steel and High-Nickel Alloys .. 283 Chapter 18 Copper and Copper Alloys . 18.1 Coppers 18.2 High-Copper Alloys 18.3 CopperZinc Alloys (Brasses).. 18.4 CopperTin Alloys 18.5 CopperAluminum Alloys. 18.6 CopperNickel Alloys 18.7 CopperBeryllium Alloys 18.8 Cast Copper Alloys . 18.8.1 Corrosion Resistance References . 469 472 475 475 483 483 485 488 488 488 490 Chapter 19 Aluminum and Aluminum Alloys 19.1 Classications and Designations 19.2 Temper Designations.. 19.3 Strain-Hardened Subdivisions. 19.3.1 H1XStrain-Hardened Only 19.3.2 H2XStrain-Hardened and Partially Annealed. 19.3.3 H3XStrain-Hardened and Stabilized.. 19.4 Heat-Treated Subdivisions . 19.5 Chemical Composition.. 19.6 General Corrosion Resistance .. 19.7 Pitting Corrosion 19.8 Intergranular Corrosion 19.8.1 Mechanism of Intergranular Corrosion in 2XXX Alloys 19.8.2 Mechanism of Intergranular Corrosion in 7XXX Alloys 19.9 Exfoliation Corrosion . 19.10 Stress Corrosion Cracking .. 19.11 Filiform Corrosion. 19.12 Crevice Corrosion . 19.13 Poultice Corrosion 19.14 Galvanic Relations 19.15 Reduction of Ions of Other Metals by Aluminum 19.16 Weathering . 491 492 493 494 494 494 494 494 495 499 500 506 8243Prelims10/11/200618:40CRCPAG14180XML MODEL B pp. Its chemical composition is shown in Table 9.1. Schweitzer. On average, the general corrosion resistance is below that of type 304 stainless. For this form of attack to occur, there must be a specic environment. Airborne dust that has settled on the steel surface may prompt corrosion by absorbing SO2 and water vapor from the atmosphere. 123132 Ferritic Stainless Steel Family 131 TABLE 7.4 Continued Type of Alloy Chemical Sodium hydroxide, conc. Molten tin at 2488F (1208C) has induced LME in austenitic stainless steels. Devoted to the latest research on mechanisms of corrosion and advancements in corrosion resistance, the updatedfifth edition accounts for recent advances and offers a convenient, single-source tabular guide to materials used in the construction of all system components- from vessels to pumps to gaskets and packing- for processes and applications. Although the strength of this alloy is higher than that of type 304, its corrosion resistance is inferior. It occurs when the protective lm breaks down in small isolated spots, such as when halide salts contact the surface. The widely different compositions result in a range of properties. It is important for the end user to be familiar with how various components are fabricatedfrom castings, forgings, bar stock, or whatever the case may be. Carbon steel is susceptible to stress corrosion cracking (SCC) in the presence of hydroxides, gaseous hydrogen, hydrogen chloride, hydrogen bromide, hydrogen sulde gas, and aqueous nitrite solutions, even in low concentrations. Overmatching weld ller materials are generally used for weld repairs and fabrication welds.11 American Welding Society (AWS) ller metal grades NiCrMo-3, NiCrMo-7, NiCrMo-10, and NiCrMo-12 are the most commonly used grades.12,13 Welding with matching ller requires re-solution heat treatment after all welding.

Sitemap 1

corrosion resistance tables schweitzer pdf