Machinery's Handbook, 31st Edition
1484 MATERIALS FOR IRON AND STEEL CASTING designations and nominal chemical composition ranges of high-alloy castings which may be classified according to heat or corrosion resistance. The grades given in these tables are recognized in whole or in part by the Alloy Casting Institute (ACI), the American Society for Testing and Materials (ASTM), and the Society of Automotive Engineers (SAE). Table 2. Nominal Chemical Composition and Mechanical Properties of Heat-Resistant Steel Castings ASTM A297-17
Tensile Strength, min
0.2 Percent Yield Strength, min
Percent Elongation in 2 inch, or 50 mm, min.
Nominal Chemical Composition, Percent a
Grade
ksi
MPa
ksi 35 35 35 35 40
MPa 240 240 240 240 275
HF HH HI HK HE HT HU HW HX HC HD HL HN HP
19 Chromium, 9 Nickel 25 Chromium, 12 Nickel 28 Chromium, 15 Nickel 25 Chromium, 20 Nickel 29 Chromium, 9 Nickel 15 Chromium, 35 Nickel 19 Chromium, 39 Nickel 12 Chromium, 60 Nickel 17 Chromium, 66 Nickel 28 Chromium, 5 Nickel 29 Chromium, 20 Nickel 20 Chromium, 25 Nickel 26 Chromium, 35 Nickel 28 Chromium
70 485 75 515 70 485 65 450 85 585 65 450 65 450 60 415 60 415 55 380 75 515 65 450 63 435 62.5 430 76 525
25 10 10 10
9 4 4
… … … …
… … … … … … … … …
35 35 34 33 25
240 240 235 225 170
8
10
… …
8
4.5
HG 10 MNN 19 Chromium, 12 Nickel, 4 Manganese
20 20
CT15C
20 Chromium, 33 Nickel, 1 Niobium 63 435
ksi = kips per square inch = 1000s of pounds per square inch; MPa = megapascals. a Remainder is iron.
The specifications committee of the Steel Founders Society issues a Steel Castings Handbook with supplements. Supplement 1 provides design rules and data based on the fluidity and solidification of steel, mechanical principles involved in production of molds and cores, cleaning of castings, machining, and functionality and weight aspects. Data and examples are included to show how these rules are applied. Supplement 2 summarizes the standard steel castings specification issued by the American Society for Testing and Materials (ASTM), Society of Automotive Engineers (SAE), Association of American Railroads (AAR), American Bureau of Shipping (ABS), and Federal authorities, and provides guidance as to their applications. Information is included for carbon and alloy cast steels, high alloy cast steels, and centrifugally cast steel pipe. Details are also given of standard test methods for steel castings, including mechanical, non-destructive (visual, liquid penetrant, magnetic particle, radiographic, and ultrasonic), and testing of qualifications of welding procedures and personnel. Other supplements cover such subjects as tolerances, drafting practices, properties, repair and fabrication welding, of carbon, low alloy and high alloy castings, foundry terms, and hardenability and heat treatment. Austenitic Manganese Cast Steel: Austenitic manganese cast steel is an important high- alloy cast steel which provides a high degree of shock and wear resistance. Its composition normally falls within the following ranges: carbon, 1.00 to 1.40 percent; manganese, 10.00 to 14.00 percent; silicon, 0.30 to 1.00 percent; sulfur, 0.06 percent max.; phospho rus, 0.10 percent, max. In the as-cast condition, austenitic manganese steel is quite brittle. In order to strengthen and toughen the steel, it is heated to between 1830 and 1940 ° F (999 and 1060 ° C) and quenched in cold water. Physical properties of quenched austen itic manganese steel that has been cast to size are as follows: tensile strength, 80,000– 100,000 psi(552–689 MPa); shear strength (single shear), 84,000 psi(579 MPa); elonga tion in 2 inches(50.8 mm), 15 to 35 percent; reduction in area, 15 to 35 percent; and 180 to 220 BHN (Brinell Hardness Number). When cold-worked, the surface of such a casting increases to a hardness of 450 to 550 BHN. In many cases the surfaces are cold-worked to
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