Forgings for oil and gas are bought on four things: the material grade, the heat treatment, the tests performed and the traceability from the melt to the finished part. If any of the four is missing from the paperwork, a buyer cannot show that the part is fit for pressure service.
Typical parts are flanges, fittings, valve bodies, shafts and wellhead components. This guide explains what to ask Indian forging suppliers for and how to check it.
Which grades and standards apply?
Carbon steel, low-alloy steel and stainless steel are the usual families, with special alloys for sour or high-temperature service. The grade is set by the product standard that your customer or project names, so write that standard on the purchase order rather than a loose description.
Many projects also add a client specification on top of the standard, with extra limits on chemistry, impact toughness or hardness. Read it before you quote. Our note on steel grades for forgings lists common grades and what they suit.
Why does heat treatment matter so much?
Forging sets the shape, but heat treatment sets the properties. Normalising, quenching and tempering, or solution annealing for stainless steel, give the strength and toughness that the standard requires. A forging that skips or botches this step can pass a dimensional check and still fail in service.
Ask for the furnace record: temperature, time, quench medium and the furnace calibration status. See heat treatment for forgings for what a good record shows.
What tests should the forging pass?
The required tests depend on the standard and the service. Buyers commonly ask for the following:
- Chemical analysis from the melt, and often a check on the finished part.
- Tensile test for yield, tensile strength and elongation, taken from a test coupon or the forging itself.
- Impact testing at a stated temperature, for low-temperature or critical service.
- Hardness testing on the finished part, particularly where sour service limits are set.
- Non-destructive testing such as ultrasonic or magnetic particle inspection, to the stated acceptance level.
What does traceability mean in practice?
Every forging should carry a heat number, stamped or marked, that links it to a melt certificate and to the test records. The documents then follow the part from the steel mill through the forge, the heat-treatment shop and the machine shop.
Check that the heat number on the part matches the certificate, and that the certificate is issued to the correct type under EN 10204. Many oil and gas buyers ask for a type 3.1 certificate, and some for a type 3.2 verified by a third party. Confirm which your project needs.
How do you reduce the risk?
Audit the forge and its testing, not only its sales office. Ask who does the non-destructive testing and whether those inspectors are qualified. Check that the laboratory is calibrated and that the supplier does not subcontract critical steps without telling you.
Where a client or regulator requires it, appoint a third-party inspector to witness tests and release the lot. Our guide to reading a lab certificate helps you review the paperwork yourself.
Next step
We can shortlist forgers who work to your specification, audit them, check samples and have lots tested before shipment. To start, book a free sourcing review.