Introduction
The steel used for forging the rotors and shafts of the combustors used in American gas turbines is a critical part of keeping the turbine running efficiently and safely. As such, the grade of steel selected for forging these critical components must meet performance criteria as specified by the engine manufacturer. In this paper, we will discuss the types of steel used in forging rotor and shaft components of combustors used in American gas turbine engines and the performance criteria that must be met by the steel.
Types of Steel Used in Forging Turbine Rotors and Shafts
The most commonly used steel grades for forging combustor components in American gas turbine engines are 4330 and 4340. Both alloys are air-hardening medium-carbon steels with relatively high strength and good toughness. 4330 is used mostly for forgings, whereas 4340 is less expensive and often used for shafts. In addition, 4330 and 4340 also offer good resistance to atmospheric corrosion and to wear.
For firmer and higher strenght steels, 4350 and 52100 are used in some instances. 4350 is a chromium and nickel alloy that offers good corrosion resistance and stability at elevated temperaturs and is often used when embrittlement is a concern. 52100 is a chromium alloy steel that has been heat treated for superior strength and wear resistance.
Performance Criteria for Steel Used in Forging Turbine Rotors and Shafts
The steel used for forging turbine rotors and shafts must meet stringent performance criteria in order to maintain the safety and performance of the combustor. The criteria include:
A) Tensile Strength: The tensile strength of the steel must be sufficient to ensure that the components can withstand the high stresses they will encounter while operating.
B) Yield Strength: The steel must be able to withstand a certain amount of load before undergoing permanent deformation.
C) Resistance to Corrosion: The steel must resist not only atmospheric corrosion, but also corrosion caused by the gases used in the engine.
D) Resistance to Wear: The steel must also fire resistant and wear-resistant so that the components can stand up to the high temperatures and pressures of the engine.
Conclusion
The steel used in forging turbine rotors and shafts of American gas turbine engines must meet stringent performance criteria in order to maintain the safety and performance of the combustor. The most commonly used steel alloys for forging combustor components in American gas turbine engine are 4330, 4340, 4350 and 52100. Each alloy offers its own resistance to corrosion and wear, as well as the strength needed to meet the engine performance requirements. By selecting the correct steel grade, the combustor components can operate efficiently and safely for many years.
