B50A790(410Cb), 403Cb, XM-30, UNS 41040 is an AOD + ESR melted martensitic stainless steel alloy. this alloy has elevated strength and toughness as compared to standard 410. The addition of columbium allows for improved grain size control and greater ease in heat treating. This grade is used primarily in the power generation market, Steam Turbine buckets and partitions, Gas Turbine compressor blades, bolting and other miscellaneous components.
AOD+ESR
| Grade | Chemical composition WT % | ||||||
|---|---|---|---|---|---|---|---|
| C | Mn | Si | P | S | Cr | Cb | |
| 410Cb, B50A790(410Cb), XM-30 | Max 0.18 | Max 1.0 | Max 1.0 | Max 0.03 | Max 0.03 | 11.50 - 12.50 | 0.05 - 0.20 |
| Condition of heat treatment | Tensile Rm(MPa) | Yield Rp0.2(MPa) | Elongation A(%) | Reduction in cross section on fracture Z (%) | Impact AKV/AKU(J) | Brinell Hardness(HBW) |
|---|---|---|---|---|---|---|
| Annealed | - | - | - | - | - | - |
| Q+T 1136℃~1163℃, ≥677℃ X 2h tempered | Min 795 | Min 515 | Min 15.0 | Min 50.0 | Min 35 | Min 277 |
Fast air cooled and tempered directly after hot working or re-austenitized at 1600-1750°F for two hours minimum,quenched in oil or rapidly moving air and tempered. Material ain cooled directly after hot working shall be at 1600-1750°F,as it exits the rolling mill. Tempering shall be done between 1100-1325°F followed by uniform cooling below the martensite finish temperature
Good Welding performance
Good processing performance
Steel grade
Special steel