1.1 This specification covers iron-chromium-nickel, high-alloy tubes made by the centrifugal casting process intended for use under pressure at high temperatures. 1.2 The grades of high alloys detailed in Table 1 are intended for applications requiring strength and resistance to corrosion and scaling at high temperatures. 1.3 Optional Supplementary Requirements S1 to S11 are provided; these call for additional tests to be made if desired. 1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of each other. Combining values from the two systems may result in nonconformance with the specification. TABLE 1 Chemical Requirements | Grade | Composition, % |
|---|
| Carbon | Manganese | Silicon | Chromium | Nickel | Phosphorus | Sulfur | Molybdenum |
|---|
HC30 | 0.25–0.35 | 0.5–1.0 | 0.50–2.00 | 26–30 | 4.0 max | 0.04 max | 0.04 max | 0.50 max | HD50 | 0.45–0.55 | 1.50 max | 0.50–2.00 | 26–30 | 4–7 | 0.04 max | 0.04 max | 0.50 max | HE35 | 0.30–0.40 | 1.50 max | 0.50–2.00 | 26–30 | 8–11 | 0.04 max | 0.04 max | 0.50 max | HF30 | 0.25–0.35 | 1.50 max | 0.50–2.00 | 19–23 | 9–12 | 0.04 max | 0.04 max | 0.50 max | HH30 | 0.25–0.35 | 1.50 max | 0.50–2.00 | 24–28 | 11–14 | 0.04 max | 0.04 max | 0.50 max | HH33A | 0.28–0.38 | 1.50 max | 0.50–2.00 | 24–26 | 12–14 | 0.04 max | 0.04 max | 0.50 max | HI35 | 0.30–0.40 | 1.50 max | 0.50–2.00 | 26–30 | 14–18 | 0.04 max | 0.04 max | 0.50 max | HK30 | 0.25–0.35 | 1.50 max | 0.50–2.00 | 23–27 | 19–22 | 0.04 max | 0.04 max | 0.50 max | HK40 | 0.35–0.45 | 1.50 max | 0.50–2.00 | 23–27 | 19–22 | 0.04 max | 0.04 max | 0.50 max | HL30 | 0.25–0.35 | 1.50 max | 0.50–2.00 | 28–32 | 18–22 | 0.04 max | 0.04 max | 0.50 max | HL40 | 0.35–0.45 | 1.50 max | 0.50–2.00 | 28–32 | 18–22 | 0.04 max | 0.04 max | 0.50 max | HN40 | 0.35–0.45 | 1.50 max | 0.50–2.00 | 19–23 | 23–27 | 0.04 max | 0.04 max | 0.50 max | HT50 | 0.40–0.60 | 1.50 max | 0.50–2.00 | 15–19 | 33–37 | 0.04 max | 0.04 max | 0.50 max | HU50 | 0.40–0.60 | 1.50 max | 0.50–2.00 | 17–21 | 37–41 | 0.04 max | 0.04 max | 0.50 max | HW50 | 0.40–0.60 | 1.50 max | 0.50–2.00 | 10–14 | 58–62 | 0.04 max | 0.04 max | 0.50 max | HX50 | 0.40–0.60 | 1.50 max | 0.50–2.00 | 15–19 | 64–68 | 0.04 max | 0.04 max | 0.50 max | A Manufacturing control should ensure that this composition contain a minimal amount of ferrite. See Supplementary Requirement S5. |