GTAW · Low-alloy steel
ER90S-B3
The higher alloy chrome-moly torch rod, used on the piping grades that run hotter than the lower chromium class can handle, typically with preheat and heat treatment.
What the designation means
Point at any character to see what it claims. The classification is a sentence written in fields, not a product name.
- ERClassified as both an electrode and a hand fed filler rod.
- 9090,000 psi minimum tensile strength of the deposit.
- SSolid rod or wire.
- -B3A chromium-molybdenum chemistry class at nominally 2.25 percent chromium and 1 percent molybdenum.
At a glance
- Process
- GTAW
- Family
- Low-alloy steel
- Positions
- All positions
- Polarity
- DCEN
- Shielding
- Welding grade argon at the torch, plus an inert back purge on pipe roots
- Minimum tensile
- 90ksi
Typical uses
- Root passes on 2.25 chromium 1 molybdenum high temperature piping
- Power plant headers and hot reheat lines
- Hydroprocessing reactor piping in refineries
How it runs
- Higher hardenability than the lower chromium class, so preheat is essential
- Clean, precise puddle suited to open root work
- Post weld heat treatment is normally required to reach specified properties
- Root must be fully purged to prevent oxide on the inside surface
Storage and handling
Store rods in the sealed tube in a dry area and keep them free of oil and rust; contamination shifts the alloy chemistry in the deposit.
Compare with
GTAWER80S-B2The chrome-moly torch rod used for root passes on lower alloy high temperature piping, matched to the same alloy class as the companion covered electrode.SMAWE9018-B3The next step up in the chrome-moly family, carrying roughly twice the chromium of the lower class for higher temperature and higher pressure piping.GMAWER70S-2The most heavily deoxidised of the common carbon steel wires, which is why it tolerates rust and mill scale and is the standard pick for open root passes.