GH3030 solid solution strengthened superalloy is an early developed 80Ni-20Cr solid solution strengthened superalloy with simple chemical composition, satisfactory thermal strength and high plasticity below 800 °C, and good resistance to oxidation, thermal fatigue, Cold stamping and welding process performance. The alloy is single-phase austenite after solution treatment, and the structure is stable during use. The main product is cold rolled sheet, but also deformed products such as bar, ring, wire and tube can be supplied. It is mainly used for turbine engine combustion chamber components that work below 800 °C and other high-temperature components that require oxidation resistance below 1100 °C but bear small loads. GH3030 has strong thermal processing and cold processing properties, and is used to make various chemical equipment and supporting accessories.
Chemical Composition
| C | Cr | Ni | Ti | Al | Fe | Mn | Si | P | S |
| ≤0.12 | 19.0～22.0 | reminder | 0.15～0.35 | ≤0.15 | ≤1.5 | ≤0.7 | ≤0.8 | ≤0.03 | ≤0.02 |
Thermal conductivity
| θ/℃ | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 |
| λ/（W/（m·C）） | 15.1 | 16.3 | 18.0 | 19.3 | 20.9 | 22.2 | 23.4 | 25.1 | 26.4 |
Specific Heat Capacity
| θ/℃ | 150 | 200 | 300 | 400 | 500 | 600 |
| c/(J/(kg.K)) | 565.2 | 598.7 | 674.1 | 741.1 | 820.6 | 971.3 |
Linear expansion coefficient
| θ/℃ | 20～100 | 20～200 | 20～300 | 20～400 | 20～500 | 20～600 | 20～700 | 20～800 | 20～900 |
| α/10-6C-1 | 12.8 | 13.5 | 14.3 | 15.0 | 15.5 | 16.1 | 17.0 | 17.5 | 18.0 |
Electrical properties
Resistivity at different temperatures
| θ/℃ | 20 | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 |
| ρ/(10-6Ω.m) | 1.090 | 1.099 | 1.108 | 1.117 | 1.127 | 1.153 | 1.135 | 1.126 | 1.123 |
Process performance
1. The alloy has good forgeability, the forging heating temperature is 1180℃, and the final forging is 900℃.
2. The average grain size of the alloy is closely related to the deformation degree and final forging temperature of the forging.
3. After heat treatment, the oxide scale on the surface of the parts can be removed by sand blowing or pickling.
Control of Oxygen and Nitrogen Content in GH3030 Smelting
(1) The refining parameters have a very important influence on the oxygen and nitrogen content in the GH3030 liquid. When the refining vacuum degree is 30Pa, the refining temperature is 1510℃, and the refining time is 15 minutes, the oxygen content in the GH3030 liquid reaches the minimum value, and the nitrogen content in the GH3030 liquid decreases with the increase of the refining temperature and the prolongation of the refining time.
(2) The addition of deoxidizer carbon is beneficial to the removal of oxygen and nitrogen in the GH3030 solution. Therefore, within the allowable range of the chemical composition of the produced steel, the addition amount of carbon should be increased as much as possible. The final addition amount of carbon in this experiment is 0.08% (quality score).
(3) The removal of 60% - 90% oxygen and 62.5% - 87% nitrogen occurs in the melting period, so the purpose of removing a large amount of oxygen and nitrogen content in GH3030 liquid can be achieved by appropriately reducing the melting speed.
(4) The influence of the type and addition ratio of the returned material on the oxygen and nitrogen content in the GH3030 liquid is equally important. The adverse effect of the sawdust is greater than that of the shavings and the riser. It should be used according to the product requirements.
