Seeing lab heats of Cr–Mn–Ni–N austenitic stainless reach 0.2% yield around 600 MPa at room temp with nickel under 2 wt% by pushing nitrogen near 0.35, while keeping PREN about 20–21. Has anyone else trialed these lean chemistries this quarter, and how are you balancing Mn and N for austenite stability versus hot workability and weld porosity?
how are you balancing Mn and N for austenite stability versus hot workability and We held N at about 0.30 with Mn about 10.5, and the single biggest win was 1.5–2% N2 in Ar for GTAW/GMAW shielding/backing — porosity vanished while YS stayed about 600 MPa; over about 3% N2 we saw pores again — what % are you running?
My take: I’d lean toward the simplest next step and see if it changes anything this week — if not, you’ve got a clear case to escalate. What would block you from trying that?
Pressurized AOD (2–3 bar N2) kept ‘0.35 N’ and improved hot ductility, @amanda_w27.
We hit “600 MPa 0.2%” at Ni about 1.8 and N about 0.33, but hot workability only settled down after capping Mn at about 9.2 and adding 20–30 ppm B; a 1130°C solution anneal with a hard water quench cut Cr2N and edge cracking. Weld porosity still drives me nuts — N‑bearing filler (ER200N) plus tight backpurge helped more than cranking torch N; quick read: https://www.twi-global.com/technical-knowledge/job-knowledge/nitrogen-in-stainless-steel-welding-014. @amanda_w27, have you tried the Mn drop with PREN 20–21 or does your spec lock Mn higher?