Corrosion-resistant steels

Germany, the United Kingdom, and the United States shared ahke in the early development of stainless steels. In the United Kingdom in 1912, during the search for steel that would resist fouling in gun barrels, a corrosion-resistant composition containing 12.8% chromium and 0.24% carbon was reported. It was suggested that this composition be used for cutiery. In fact, the composition of AISI Type 420 steel (12—14% chromium, 0.15% carbon) is similar to that of the first corrosion-resistant steel. 

Special quality steels - A vast range of special quality steels is made in electric arc furnaces by adding other metals to form steel alloys. The most commonly known of these is stainless steel, which has chromium and nickel added to form a corrosion-resistant steel. There are very many others however the very hard steels used to make machine tools, the steels specially formulated to make them suitable for engineering, steels developed to survive for decades the hostile environment of nuclear reactors, light but strong steels used in aerospace, extra tough steels for armor plating - to name but a few. 

In aluminum castings, integral corrosion-resistant steel inserts may be used. An example is shown in Figure 2.3. 

Figure 2.3. Example of a corrosion-resistant steel insert used in an aluminum casting.

Levin, I. A. and Volikova, 1. G., The Accelerated Method for Testing the Stability of a Singlephase Corrosion Resistant Steel to Intercrystalline Corrosion , ZavodskLab., 30, 816 (1964) Hua, P.-T., Shen, H.-S., Chou, C. C. and Chung, T. T., Relation Between Intercrystalline Corrosion and Electrode Potential of Austenitic Stainless Steel , K O Hsueh Tung Pao, 2, 56 (1964) C.A., 60, 15516h... 

Herbsleb, G. and Schwenk, W., Electrochemical Study of the Pitting Corrosion of Corrosion-resistant Steels , Werkst. Korros., 24, 763 (1973) C.A., 88. 21970h Poatsch, W., Optical Studies of the Mechanism of Pitting Corrosion , Ber. Bunsenges Phys. Chem., 77, 895 (1973) C.A., 80, 90201v... 

Smith, E., Corrosion Resisting Steels—Application in the Pickle and Sauces Industry, B.F.M.I.R.A., Scientific and Technical Survey, December (1950)... 

Treadaway, K. W. J., Cox, R. N. and Brown, B. L., Durability of corrosion resisting steels for reinforced concrete. Proceedings of the Institute of Civil Engineers (in press)... 

An interesting development in weldable corrosion-resistant steels is the copper-bearing or weathering steels (Section 3.2) which exhibit enhanced corrosion resistance in industrial atmospheres in the unpainted condition. For optimum corrosion resistance after welding, the filler employed should be suitably alloyed to give a deposit of composition similar to that of the steel plate... 

Materials of construction must he corrosion resistant. Steel should he hot galvanized, although some resin coatings may suffice. GRP casings are used hy some manufacturers. The water-dispersal packing of a cooling tower is made of treated timber or corrugated plastic sheet. 

Vanadium is an excellent alloy metal with iron that produces hard, strong, corrosion-resistant steel that resists most acids and alkali. It is even more resistant to seawater corrosion than is stainless steel. Vanadium is difficult to prepare in a pure form in large amounts. Impure forms seem to work as well as a very pure form of the metal when used as an alloy. When worked as a metal, it must be heated in an inert atmosphere because it will readily oxidize. 

The range of suitable high-strength and corrosion-resistant steels can be extended by alloyed titanium types and others. 

Only vessels for small units are completley made of corrosion- resistant material. This protection method is to expensive for large vessels. They can be more economically protected by a liner of corrosion-resistant material containing Mo, Cr, Ni and V. Multilayer vessels require corrosion-resistant steel only for the innner layer. They are often equipped with venting channels, so-called Bosch-holes to ensure that for example hydrogen diffusing through the inner layer is drained and could be analysed. 

Part 1, p 874, Test A262-44T ("Tentative Recommended Practice for Boiling Nitric Acid Test for Corrosion-Resisting Steels ) Part 1, p 878, Test A279-44T (Total Immersion Corrosion Test for Stainless Steels) 18) Kirk Othmer 4 (1949)... 

Chromium, which gets its name from the Greek word for color (chroma), is obtained from the ore chromite, a mixed metal oxide with the formula FeO Cr203, or FeCr204. Reduction of chromite with carbon gives the alloy fer-rochrome, which is used to make stainless steel, a hard, corrosion-resistant steel that contains up to 30% chromium. 

Copper, low brasses or bronze silver solder Ni-Cr alloys austenitic corrosion-resistant steels -0.20 0.35 ... 

Fatigue data of corrosion resistant steels and other relevant high strength materials are easy available for non-corrosive ambiance (air, oil). For the large variety of liquids applied in production processes the data have to be evaluated from special fatigue tests with corrosion cells. This paper answers the question if such uniaxial test results can be applied for the real component design in order to meet three-axial corrosion fatigue reality well. 

This specification pertains to carbon steel vessels, but may be used where more corrosion-resistant steel or alloy materials are used for vessel construction. 

Anti-wear and load-carrying additives work by reacting with ferrous metal surfaces. The metal surfaces have to be sufficiently reactive themselves for the additive to work, which is the case with traditional steels such as M50 and M50 NiL but problems are encountered with more corrosion-resistant steels. These steels are designed to be chemically less reactive to inhibit corrosion but this affects the ability of the anti-wear additive to react with the metal surface. It is desirable to use these corrosion-resistant steels in engine design and the quest for an additive system that works with corrosion-resistant steels, without adversely affecting other areas of performance, is currently the subject of much research in the aero-engine lubrication community. 

In the late 1970 s substrates derived from ultra thin foils of corrosion resistant steels were offered onto the market. The foils could be made from material only 0.05 mm thick allowing high cell densities to be achieved. In their early application they were mounted in locations inside the exhaust manifold but they are now used in other locations as well. Complex internal structures can be developed and wall thickness is down to 0.04 mm and cell densities of 600 cpsi standard production. 

SXXXXX.Heat and Corrosion Resistant Steels (Including... 

ASTMA32S Type 3 See Note 3 High-strength structural bolts Atmospheric corrosion resisting steel, quenched and tempered... 

---