02.Classifications and Specifications

1 of 8Steel Castings Revised by Malcolm Blair, Steel Founders' Society of America <Previous section in this article Next section in this article> Classifications and Specifications The steel castings discussed in this article are divided into four general groups according to composition: Low-carbon steel castings Medium-carbon steel castings High-carbon steel castings Low-alloy steel castings Other types of steel castings are discussed in separate articles on heat-resistant castings, stainless (corrosion-resistant) steel castings, and austenitic manganese steels in this Volume. Carbon steels contain only carbon as the principal alloying element. Other elements are present in small quantities, including those added for deoxidation. Silicon and manganese in cast carbon steels typically range from 0.25 to about 0.80% Si and 0.50 to about 1.00% Mn. Like wrought steels, carbon cast steels can be classified according to their carbon content into three broad groups: Low-carbon steels: 0.20% C or less Medium-carbon steels: 0.20 to 0.50% C High-carbon steels: 0.50% C or more Carbon content is a principal factor affecting the mechanical properties of these steels. The other important factor is the method of heat treatment. Figure 1 shows the basic trends of the mechanical properties of cast carbon steels as a function of carbon content for four different heat treatments. For a given heat treatment, a higher carbon content generally results in higher hardness and strength levels with lower ductility and toughness values. Further information on the properties of carbon cast steels is contained in subsequent sections of this article. . titanium. Of these elements. and zirconium are used for the deoxidation of low-alloy steels. (a) Tensile strength and reduction of area. % 1. 1 Properties of cast carbon steels as a function of carbon content and heat treatment. in addition to carbon. (b) Yield strength and elongation.05 Aluminum. (d) Charpy V-notch impact energy Low-alloy steels contain. alloying elements up to a total alloy content of 8%. aluminum is used most frequently because of its effectiveness and low cost.25 0.2 of 8 Fig.00 0.05 0.10 0.50 0.80 0. Cast steels containing more than the following amounts of a single alloying element are considered low-alloy cast steel: Element Manganese Silicon Nickel Copper Chromium Molybdenum Vanadium Tungsten Amount.50 0. (c) Brinell hardness. . and 9200 (silicon)..06% S... 4000 (molybdenum)..06% S. do not precisely follow the compositional ranges specified by AISI and SAE designations for wrought steels. % C Mn Si Class or grade Other requirements Condition or specific application ASTM A 27: carbon steel castings for general applications N-1 N-2 U60-30 60-30 65-35 70-36 70-40 .05% P 0. 5100 (chromium).50 to 1. 0.35(c) 0..05% P 0.75(c) 0.. Table 1 Summary of specification requirements for various carbon steel castings Unless otherwise noted.65% Si and 0. nickel. . molybdenum 80B00 2300 Manganese..06% S. . 60 60 65 70 70 ..25(c) 0. molybdenum The 8000. 30 30 35 36 40 .. molybdenum Chromium. molybdenum 9500 4100 Manganese. 2300. Table 1 primarily lists carbon steel castings (with some comparable low-alloy types).. 0.. The designations of the American Iron and Steel Institute (AISI) and the Society of Automotive Engineers (SAE) have historically been used to identify the various types of steel by their principal alloy content.80 0. . Cast steels.. boron Nickel 8600. that is. 4300 Nickel.20(c) 0. 22 24 24 22 22 . 8400 80B00 2300 8600.30 to 0. Tables 1 and 2 list the requirements given in various specifications of the American Society of Testing and Materials (ASTM) and in SAE J435c.05% P 0.30(c) 0.. 8400.30(c) 0. 0. Further information on the elements used in alloy steel castings is provided in the section "Low-Alloy Cast Steels" of this article. 6100 (chromium-vanadium).....70(c) 0.06% S. 0.05% P 0.80 0.. heat. 3300 (nickel-chromium). Specifications..045% max.05% P 0.06% S. chromium. Yield % strength(a) elongation reduction in 50 mm in MPa ksi (2 in. . The principal low-alloy cast steel designations.00% Mn. In most cases. 3100 (nickel-chromium). however.80 0.0%. the cast steel grades contain 0. 205 205 240 250 275 . with some restrictions on chemical composition.06% S.60(c) 0.80 0. 4600 (nickel-molybdenum). all the grades listed in this table are restricted to a phosphorus content of 0. and 9500 alloy types are used extensively as cast steels. . % area. while Table 2 lists several low-alloy cast steels and some cast steels with chromium contents up to 10.05% P 0. 0. 0.60(c) 0.80 0. 0. molybdenum. 0.75(c) 0. such as structural strength and resistance to wear.05% P 0. their AISI and SAE equivalents.05% P Chemical analysis only Heat treated but not mechanically tested Mechanically tested but not heat treated Heat treated and mechanically tested Heat treated and mechanically tested Heat treated and mechanically tested Heat treated and mechanically tested ASTM A 148: carbon steel castings for structural applications(d) 80-40 550 80 275 40 18 30 (e) (e) (e) 0.70(c) 1.05% P Composition and heat treatment necessary to achieve specified mechanical properties Composition and heat treatment necessary to achieve specified mechanical properties 80-50 550 80 345 50 22 35 (e) (e) (e) .25(c) 0. 8400 Manganese..40% max and a sulfur content of 0. 0.80 0. Steel castings are usually purchased to meet specified mechanical properties.3 of 8 Numerous types of cast low-alloy steel grades exist to meet the specific requirements of the end-use. and corrosion. 4300 9500 4100 1300 Manganese Alloying elements 8000. and their alloy type are: Nearest Cast steel wrought designation equivalent 1300 8000.06% S. Tensile strength(a) MPa ksi Minimum Minimum Chemical composition(b).). unless otherwise specified.06% S.06% S.35(c) 0. chromium.80 0.. 30 35 35 30 30 0.25(c) 0. . 415 415 450 485 485 .. There are additional alloy types that are infrequently specified as cast steels.. 25-0. 0.50% Cr max.40-0. (f) Purchased on the basis of hardenability. 2... . . (i) Testing temperature of -32 °C (-25 °F).. (d) Grades may also include low-alloy steels. 415 450 585 690 550 620 . (a) Where a single value is shown..50% Ni max.70(c) 0.20(c) 0.50% Ni.22 0. (g) Specified residual elements include 0...00 0. the compositions of cast steels in ASTM A 148 are selected by the producer in order to achieve the specified mechanical properties. and other heavy-walled components for steam turbines Castings for pressure-containing applications at low temperatures (g) (j) (k) .90 0.60 (g)(i)(j) Low-temperature applications Low-temperature applications Castings for valve chests. .34 . 0.25 0.90 0. (f) .06% S. . ASTM A 216: carbon steel castings suitable for fusion welding and high-temperature service WCA WCB WCC 415-585 60-85 485-655 70-95 485-655 70-95 205 250 275 30 36 40 24 22 22 35 35 35 0.70(c) 1. . (l) Specified residual elements of 0. (k) Testing temperature of -46 °C (-50 °F).30% Cu max. 0.00(c) 1.25 0.90 0.03% V. an increase of 0. with total amount not exceeding 1...80 187 HB max 0.06% S.80 131-187 HB Low carbon steel suitable for carburizing Carbon steel welding grade Carbon steel welding grade Carbon steel medium-strength grade Carbon steel medium-strength grade Medium-strength low-alloy steel Medium-strength low-alloy steel Hardenability grades (Fig.00%..05% P Composition and heat treatment necessary to achieve specified mechanical properties Composition and heat treatment necessary to achieve specified mechanical properties 105-85 725 105 585 85 17 35 (e) (e) (e) SAE J435c: see Table 2 for alloy steel castings specified in SAE J435c 0022 0025 0030 0050A 0050B 080 090 HA.60 0.035% P max..25% Mo.. .60 0..70(c) 1.. 30 35 45 70 50 60 . it is a minimum. 163-207 HB . .35 0.60 187 HB max 0.00%. throttle valves. ..40-0.50-0. .025% max Table 2 Summary of specification requirements for various alloy steel castings with chromium contents up to 10% .30 0. 0.50 (g) (g) (g) Pressure-containing parts Pressure-containing parts Pressure-containing parts Other ASTM cast steel specifications with carbon steel grades(h) A 352-LCA A 352-LCB A 356-grade 1 A 757-A1Q 415-585 60-85 450-620 65-90 485 70 205 240 250 30 35 36 24 24 20 35 35 35 0.. 0.50-0.70(c) 0.60 0.01% C below the maximum specified. 187-241 HB (f) See Fig. 0. with manganese and other elements added as required.50 0.50% Cu. it is a maximum. each 0.30(c) 0. .50 0..03% V max.. ..25 0.60 0. 0. . 0.. (h) These ASTM specifications also include alloy steel castings for the general type of applications listed in the Table.30 1.. 22 24 16 10 22 20 .. and 0.. and 0. 30 35 24 15 35 40 .. (e) Unless specified by purchaser. 207 241 310 485 345 415 . HC(f) .12-0.00 . 2) 0...40% Cr.80 207-225 HB . 0..25(c) 0.30 0. 0..50-0. 60 65 85 100 80 90 . (j) Charpy V-notch impact testing at the specified test temperature with an energy value of 18 J (13 ft · lbf) min for two specimens and an average of three.60 (j) (k) (l) 450 65 240 35 24 35 0. 0.. 0. HB.030 S max 0.05% P 0.75(c) 0. . with the total residual elements not exceeding 1....4 of 8 90-60 620 90 415 60 20 40 (e) (e) (e) 0.20% Mo max.04% Mn above the maximum specified is permitted up to the maximums given in the applicable ASTM specifications.80 170-229 HB 0. see Table 2 for the stronger grades of ASTM A 148. (c) For each reduction of 0.. Sulfur and phosphorus content. (b) Where a single value is shown. ..45-0. ..30 1. .20 0.65 0..20 0....50(n) 0. ....80 0.15-0.40 1.30-0. ..5Cu(h).. % in area. .80 0..... . . (o) (n) 0.65 0.00-1.15-0. (n) (n) (n) 0...90-1.. .25 0.80 0. .10-0...... (n) 0.. .70-1.30 .45-0. . . ..35 0.. .80 0..30 0.00 1.35 (n) 0.80 0.10-0.00 1. .00 1. (n) (i) (p) 0..20 0. .. . (h) (m) ASTM A 487: alloy steel castings (NT or QT) for pressure-containing parts at high temperatures 1A (NT) 2B (QT) 1C (NT or QT) 2A (NT) 2B (QT) 2C (NT or QT) 4A (NT or QT) 4B (QT) 4C (NT or QT) 4D (QT) 4E (QT) 585-760 620-795 620 585-760 620-795 620 620-795 85-110 90-115 90 85-110 90-115 90 90-115 380 450 450 365 450 450 415 55 65 65 53 65 65 60 85 60 75 95 22 22 22 22 22 22 20 17 20 17 15 40 45 45 35 40 40 40 35 40 35 35 0.. .30 0..30 0. .25 ... . . .80 0. . % (d) Material class(a) Composition(c).75 1.15-0. .40 1.80 0...80 0... .40-0.. .20 0.25 . .....40-0..80 0. . .40-0. .50-0..50 (i) (i) ASTM A 389: alloy steel castings (NT) suitable for fusion welding and pressure-containing parts at high temperatures C23 C24 485 550 70 80 275 345 40 50 18 15 35 35 0.80 0.30 0.30 0.60 0...80 0..50 (i) (i) . (j) (k) (i) (j) 0.. ...). ..50-0.. (e) (e) (e) (e) (f) (f) (f) (f) (f) (f) 1000 145 1035 150 1035 150 1240 180 1240 180 1450 210 1450 210 SAE J435c: see Table 1 for the carbon steel castings specified in SAE J435c(g) 0105 0120 0150 0175 725 827 1035 1207 105 120 150 175 586 655 862 85 95 125 17 14 9 6 35 30 22 12 ..70 0. ..65 0.50 0.. .....30 0..80 0. .. .50 0.50 2.40-0.40-0.30 0.. .40-0.18 0... .30 0..70 0. (h) (h) (h) (h) 1000 145 ASTM A 217: alloy steel castings for pressure-containing parts and high-temperature service WC1 WC4 WC5 WC6 WC9 WC11 C5 C12 450-620 485-655 485-655 485-655 485-655 550-725 620-795 620-795 65-90 70-95 70-95 70-95 70-95 80-105 90-115 90-115 240 275 275 275 275 345 415 415 35 40 40 40 40 50 60 60 24 20 20 20 20 18 18 18 35 35 35 35 35 45 35 35 0...90-1. .00 0.60 0.00 1.. . .. .50(i) 0.20 .30 0.35(i) 0.60 0..80 0.. ..30 0..80 0. (o) (n) 0. .10-1. . .00-6. .15-0.30-0.30 0. ..00-1..10 0.50 (n) 0. .50 0..10-1.00 0.50-0.. ..40-0. . .80 0.....50 8.. .5 of 8 Tensile strength(b) MPa ksi Minimum Yield strength(b) elongation Minimum in 50 mm reduction MPa ksi (2 in. .50 1.80 0.... .. .45-0. . . .20 (h) (m) ... ... 725-895 105-130 585 620 690 795 90 100 115 415 515 655 (k) (p) (k) (p) (k) (p) (k) (p) .60 0..30 0.00-10. .20 0.80 0.80 0.80 0. .10-1..00 1..80 0. . (i) (j) (i) (l) (i) (j) (i) (j) 0.40-0. .60 1.. .. . .... .. ..00-1.35 (i) 0.35 (i) 0.40-0. 0.. (o) 0.15-0.% C Mn Si Cr Ni Mo Other ASTM A 148: steel castings for structural applications 115-95 135-125 150-135 160-145 165-150 165-150L 210-180 210-180L 260-210 260-210L 795 930 1035 1105 1140 1140 1450 1450 1795 1795 115 135 150 160 165 165 210 210 260 260 655 860 930 95 125 135 14 9 7 6 5 5 4 4 3 3 30 22 18 12 20 20 15 15 6 6 . ..40 1... .45-0.45-0.00 0.80 0.00 0.45-0...35-0...80 0..40-0.. ... . .30 0..... .35(n) 0.80 0.21 0.. 0.60-1.40-0..40-0.5Cu(h).65 0........ ..30 0..30 0.10-0.80 0.65 (i)(j) (j) (k) 0.50 (i) 0.20 0. ..... ..50(i) 0... ..30 0......30-0.30 (k) (p) ..9-1. .40-0.25(n).90-1.... ..50-0.60 0.... ..20 0.. . .35(i) 0..20 0.25 . . .50-0.80 0. . .80 0.00 1. ..00-1...60 0.....60 0.50(i) 0..50-0. .....65 0.00 1.50 (i) (i) (p) (i) (p) 0...75 1.80 0.. .15-0. .5Cu(h). ...75 4.65 0.70 0...20 0.00-2.90 1. .80 0. . 20 0. (r) Specified elements include 0.10 0.00-1.80 0.050% Cu (max).30-0. 0.00 0.04% P (max).50-0.80 0.75-1.75-1..60-1.45-0.. .50(i) 0.00 0.00 0.65 0.30-0.10(s) (k) (p) .20 0.90-1.00-2.33 1.90 0.55-0.80 0.60 0.90 0.03% V (max). (g) Similar to the cast steel in ASTM A 148.60 0.10 2.00 0.30 (i) (p) .80 0.5 mm (2 in. (o) Includes the residual content of tungsten.002-0.40 0. 0. nickel.00%.00 0.30 1.00 0.33 0. (n) The specified residuals of copper.90-1.80-1. (p). (k) (p) (k) (p) (i) (p) .80 0.40-1.80 0.60-1. .045% S (max). . (k) (p) (p) (s) .90 0.020% P (max). 0. and 0. chromium.10 0. (q) Material class 7A is a proprietary steel and has a maximum thickness of 63.40-0.50-0. . 0. . nickel.80 0.80 0.90 0. .60 (k). 0.50% Cu (max). and vanadium.10% W (max).40-2.60%.55 0. the compositions of cast steels in ASTM A 148 are selected by the producer and therefore may include either carbon or alloy steels.60 0.80 0. and vanadium.20 0.040% P (max).10 0.50% Cu.80 0. chromium. and molybdenum (plus tungsten). (s) When residual maximums are specified for copper.75 0. (m) 0. 0. 0.70-1. 1.. (d) Unless specified by the purchaser.25% V.80 0.38 0.60-1.15-0.50-0.80-1.20 0. .75 0.00-2.40 (k) (p) . .40 1. chromium. nickel. tungsten.20-0. 0.20-0. . (r) .020% P (max). (k) When residual maximums are specified for copper.40-0.20-0.10 0.6 of 8 6A (NT) 6B (QT) 7A (QT)(q) 8A (NT) 8B (QT) 8C (QT) 9A (NT or QT) 9B (QT) 9C (NT or QT) 9D (QT) 10A (NT) 10B (QT) 11A (NT) 11B (QT) 12A (NT) 12B (QT) 13A (NT) 13B (QT) 14A (QT) 16A (NT)(u) 795 825 795 585-760 725 690 620 725 620 690 690 860 485-655 115 120 115 85-110 105 100 90 105 90 100 100 125 70-95 550 655 690 380 585 515 415 585 415 515 485 690 275 80 95 100 55 85 75 60 85 60 75 70 100 40 85 40 85 60 85 95 40 18 15 15 20 17 17 18 16 18 17 18 15 20 17 20 17 18 17 14 22 30 35 30 35 30 35 35 35 35 35 35 35 35 35 35 35 35 35 30 35 0.60-1. nickel. 0.10% W (max).30 (k) (p) .40-0.00 0. shall not exceed a total content of 1.90-1. (j) 0.30 1. 0.020% S (max. (i) When residual maximums are specified for copper.12(v) 0.50-0.50-0.10 0. it is a minimum. quenched and tempered.40-0.40-0.40 0. ..40-1.30 0.50-0.10 0.30 0.00 0.06% S (max). (h) 0. their total content shall not exceed 1. .15-0.70 0.33 0.75 2. (e) 0.40(t) 0.40 0..80 0.80 0.90-1.15-0.80 2.75 0. 725-895 105-130 585 825-1000 120-145 655 485-655 70-95 275 (p) (t) (p) (t) (s) (w) 0.40-0.40-0.15-0.80 0. (l) 0.35% Cu (max). 0.20 1.03-0.30 0.50(i) (i) (p) Composition same as 9A (NT or QT) but with a slightly higher tempering temperature 0.00 0.20(s) . .40 0.60-1.80 0.20 0.40-2. nickel.60-1.90-1. and vanadium.60-1. QT. 0. their total content shall not exceed 0. 0.04% P (max).30 0. (f) 0. chromium. (b) When a single value is shown.00 0.20 0.045% S (max).50 0.20 0. it is a maximum.60 0.015% S (max).).03% V (max).50-0.80 0.40 (t) (t) 0.20 0.50-0.80-1.006% B.60 0.00 0.80 0.38 0. tungsten.70 1.20-0.75 2.10 0. .00%.70-1.. normalized and tempered.90 0. (p) 0.10% V.00-2.80 0. their total residual content shall not exceed 0.60 0.30-1.90 0.50-0.75 0.10 0.50%.40-1. 0.55-0.30 0.10 0. (c) When a single value is shown. (a) NT.45-0.90 0.10(v) 0.70 0. see Table 1 for the lower-grade steels specified in ASTM A 148.30 1.15-0.70 0.045% S(max).20 0.75-1.70-1.60 0.30-1. 725-895 105-130 585 485-655 70-95 275 (p) (s) (p) (s) (p) (s) (p) (t) 725-895 105-130 585 620-795 90-115 415 . (k) (p) 0.80 0. 0. molybdenum.10 0. 0.05% P (max).50 (i) 0. tungsten.60-1.65 0.20-0.40-0. If only mechanical properties are specified. Table 2 lists the requirements for the low-alloy classes of steel castings given in some of the ASTM specifications mentioned above. Copyright © 2002 ASM International®. similar to ASTM A 148 105-85 or SAE 0105. a medium-carbon steel corresponding to ASTM A 27 65-35 or SAE 0030 and second. Users of steel castings for extremely critical applications. 0. 2 End-quench hardenability limits for the hardenability grades of cast steel specified in SAE J435c.7 of 8 (t) When residual maximums are specified for copper. SAE J435c includes three grades. For example. Hardenability is determined by the end-quench hardenability test described in the article "Hardenability of Carbon and Low-Alloy Steels" in this Volume. uniform response to heat treatment.80% is considered an alloy addition because it contributes significantly to resistance to tempering. Hardness is specified for most grades of SAE J435c to ensure machinability. industry association. Particularly when the purchaser heat treats a part after other processing. and HC. Railroad equipment manufacturers and other major users of steel castings may prefer their own or industry association specifications.02% V (max). The silicon content is frequently higher in cast steels than for the same nominal composition in wrought steel. hardenability is specified to ensure a predetermined degree of transformation from austenite to martensite during quenching. All Rights Reserved. 0. A 389. usually to ensure satisfactory weldability. For specific applications. both minimum and maximum. As in other steel castings. a higher-strength steel. A 217. ASTM A 703 specifies the general requirements of steel castings for pressure-containing parts. In general. may use their own. often alloyed and fully heat treated. A 356. nickel. first. an increase of 0.04% Mn is permitted up to a maximum of 2. Other specifications require minimum hardness at one or two locations on the end-quench specimen. Savings may be realized by using a grade that is standard with a foundry. The ASTM specifications that include carbon and low-alloy grades of steel castings are A 216. some specifications limit carbon and manganese content. .02% P (max) In the low-strength ranges. Manganese and other alloying elements are added as required to produce castings that meet these limits. or other requirements. Among the most commonly selected grades of steel castings are. For special applications. especially for small quantities. certain chemical composition limits have been established to ensure the development of specified mechanical properties after proper heat treatment. Fig. the chemical composition of castings for general engineering applications is usually left to the discretion of the casting supplier.10% W (max). with specified hardenability requirements. ease of inspection for high production rate items. or special-purpose military specifications. chromium. such as aircraft. HB. In SAE J435c. Foundries frequently make nonstandard grades for special applications or have their own specification system to meet the needs of the purchaser.20% Cu (max). with somewhat higher silicon permitted. carbon and manganese are specified to ensure that the minimum desired hardness and strength are obtained after heat treatment. for these steels. A 487. In addition. Silicon above 0.30% C (see Table 1). Figure 2 plots hardenability requirements. or certain characteristics pertaining to wear. 0. HA.30%. The nominal carbon content of these steels is 0. (u) Low-carbon grade with double austenitization. (w) 0. depending on the characteristics desired. This is important in critical parts requiring toughness and optimum resistance to fatigue. a casting will be ordered to compositional limits closely equivalent to the AISI-SAE wrought steel compositions. and vanadium. ASTM specifications may address common requirements of all steel castings for a particular type of application. 0. and A 757. (v) For each reduction of 0. as well as to facilitate welding.01% C below the maximum. The ASTM specifications with grades of carbon steel castings are listed in Table 1. other elements may be specified either as maximum or minimum. tungsten. in the thickness required. but to permit the foundry to utilize the silicon and manganese combination needed to achieve required soundness in the shape being cast. it is best not to specify a range of silicon. however.75%.02% S (max). their total content shall not exceed 0. A 352. 8 of 8 <Previous section in this article Next section in this article> .