Heat-resistant cast steel: chemical composition
Heat-resistant cast steels are austenitic Fe-Cr-Ni and Fe-Ni-Cr alloys (plus one ferritic-austenitic grade) designed for service at high temperature rather than for aqueous corrosion. Compared with corrosion-resistant stainless grades they carry deliberately higher carbon for creep strength and silicon for oxidation resistance; chromium protects against scaling, while rising nickel improves creep strength, carburisation resistance and tolerance of thermal cycling.
Furnace rolls, trays, baskets and fixtures for heat-treatment furnaces, radiant tubes, grate bars and burner parts, as well as reformer and cracker tubes and fittings for petrochemical plants, cement kilns and power generation.
Grades compared (mass %)
| Grade | Material no. | Standard | C | Si | Mn | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|---|---|
| GX25CrNiSi20-14 | 1.4832 | EN 10295 | 0.15–0.35 | 0.50–2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.03 | 19.0–21.0 | 13.0–15.0 | ≤ 0.50 |
| GX40CrNiSi25-12 | 1.4837 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.03 | 24.0–27.0 | 11.0–14.0 | ≤ 0.50 |
| GX40CrNiSi25-20 | 1.4848 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.03 | 24.0–27.0 | 19.0–22.0 | ≤ 0.50 |
| GX40CrNiSi27-4 | 1.4823 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 1.50 | ≤ 0.04 | ≤ 0.03 | 25.0–28.0 | 3.00–6.00 | ≤ 0.50 |
| GX40NiCrSi35-26 | 1.4857 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.03 | 24.0–27.0 | 33.0–36.0 | ≤ 0.50 |
| GX40NiCrSiNb35-26 | 1.4852 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.03 | 24.0–27.0 | 33.0–36.0 | ≤ 0.50 |
| HF | – | ASTM A297 | 0.20–0.40 | ≤ 2.00 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 18.0–23.0 | 8.00–12.0 | ≤ 0.50 |
| HH | – | ASTM A297 | 0.20–0.50 | ≤ 2.00 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 24.0–28.0 | 11.0–14.0 | ≤ 0.50 |
| HI | – | ASTM A297 | 0.20–0.50 | ≤ 2.00 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 26.0–30.0 | 14.0–18.0 | ≤ 0.50 |
| HK | – | ASTM A297 | 0.20–0.60 | ≤ 2.00 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 24.0–28.0 | 18.0–22.0 | ≤ 0.50 |
| HK40 | UNS J94204 | ASTM A351 | 0.35–0.45 | ≤ 1.75 | ≤ 1.50 | ≤ 0.04 | ≤ 0.04 | 23.0–27.0 | 19.0–22.0 | ≤ 0.50 |
| HPNb | UNS N28701 | ASTM A608 | 0.38–0.45 | 0.50–1.50 | 0.50–1.50 | ≤ 0.03 | ≤ 0.03 | 24.0–27.0 | 34.0–37.0 | ≤ 0.50 |
| HT | – | ASTM A297 | 0.35–0.75 | ≤ 2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 15.0–19.0 | 33.0–37.0 | ≤ 0.50 |
| HU | – | ASTM A297 | 0.35–0.75 | ≤ 2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 17.0–21.0 | 37.0–41.0 | ≤ 0.50 |
| HW | – | ASTM A297 | 0.35–0.75 | ≤ 2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 10.0–14.0 | 58.0–62.0 | ≤ 0.50 |
| HX | – | ASTM A297 | 0.35–0.75 | ≤ 2.50 | ≤ 2.00 | ≤ 0.04 | ≤ 0.04 | 15.0–19.0 | 64.0–68.0 | ≤ 0.50 |
| GX40CrSi28 | 1.4776 | EN 10295 | 0.30–0.50 | 1.00–2.50 | ≤ 1.00 | ≤ 0.04 | ≤ 0.03 | 27.0–30.0 | ≤ 1.00 | ≤ 0.50 |
| GX130CrSi29 | 1.4777 | EN 10295 | 1.20–1.40 | 1.00–2.50 | 0.50–1.00 | ≤ 0.035 | ≤ 0.03 | 27.0–30.0 | ≤ 1.00 | ≤ 0.50 |
Heat-resistant cast steel: cast and machined in-house
We produce heat-resistant castings by sand casting, and by centrifugal casting for cylindrical parts such as rings, bushings and sleeves. Every heat is analysed by OES; heat treatment, CNC machining in the group's Perama machine shop and EN 10204 3.1 certificates are available.
- Sand casting at our foundry in Mandra, Attica; centrifugal casting for bushings, sleeves and liners
- Heat treatment at the foundry (water, oil or air quench); CNC machining in our machine shop in Perama
- Spectrometer analysis of every heat, mechanical testing and NDT
- EN 10204 3.1 inspection certificates; ISO 9001 (both plants) and ISO 14001 (foundry) certified
All alloy families
For information only, without warranty: limits per the cited standard or, where stated, typical or house values; ≈ marks a comparable grade, not an equivalent. The current edition of the standard, the purchase order and the drawing govern.