Реферат

This specification covers the standard for iron-chromium-nickel, high-alloy tubes made by the centrifugal casting process intended for use under pressure at high temperatures. The tubing shall be supplied in the as cast condition or as cast with machining on the outside or inside surfaces. The material shall conform to the required chemical composition in carbon, manganese, silicon, chromium, nickel, phosphorus, sulfur, and molybdenum. Tension test shall be performed in the tubing at elevated temperature and shall conform to the required values in tensile strength and elongation. Tubing shall meet several tests such as; pressure test, flattening test, and mechanical test.

Область применения

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

GradeComposition, % CarbonManganese Silicon Chromium NickelPhosphorus Sulfur Molybdenum HC300.25–0.350.5–1.00.50–2.0026–304.0 max0.04 max0.04 max0.50 max HD500.45–0.551.50 max0.50–2.0026–304–70.04 max0.04 max0.50 max HE350.30–0.401.50 max0.50–2.0026–308–110.04 max0.04 max0.50 max HF300.25–0.351.50 max0.50–2.0019–239–120.04 max0.04 max0.50 max HH300.25–0.351.50 max0.50–2.0024–2811–140.04 max0.04 max0.50 max HH33^A0.28–0.381.50 max0.50–2.0024–2612–140.04 max0.04 max0.50 max HI350.30–0.401.50 max0.50–2.0026–3014–180.04 max0.04 max0.50 max HK300.25–0.351.50 max0.50–2.0023–2719–220.04 max0.04 max0.50 max HK400.35–0.451.50 max0.50–2.0023–2719–220.04 max0.04 max0.50 max HL300.25–0.351.50 max0.50–2.0028–3218–220.04 max0.04 max0.50 max HL400.35–0.451.50 max0.50–2.0028–3218–220.04 max0.04 max0.50 max HN400.35–0.451.50 max0.50–2.0019–2323–270.04 max0.04 max0.50 max HT500.40–0.601.50 max0.50–2.0015–1933–370.04 max0.04 max0.50 max HU500.40–0.601.50 max0.50–2.0017–2137–410.04 max0.04 max0.50 max HW500.40–0.601.50 max0.50–2.0010–1458–620.04 max0.04 max0.50 max HX500.40–0.601.50 max0.50–2.0015–1964–680.04 max0.04 max0.50 max

^A Manufacturing control should ensure that this composition contain a minimal amount of ferrite. See Supplementary Requirement S5.