or can it also be 4130, 4145, 410, 420, or something else?
Any grade can be produced to meet the properties of spec L80, including 4130, 4340, etc
The steel grade will set the alloy requirements, and API 80 will set the physical requirements.
The properties requirements of spec L80 are:
Minimum Yield Strength: 80,000 psi
Maximum Yield Strength: 95,000 psi
Minimum Tensile Strength: 95,000 psi
Hardness Requirement: 23 HRC maximum
Notes: Manufactured to API specification 5CT. This is a controlled yield strength material with a hardness testing requirement. L80 is usually used in wells with sour (H2S) environments.
What is the difference between an L80 4130 and an LN80 4130?