ASSAB 718H
Alloy SteelASSAB 718H / 合,
Applications
Bar, Plate, Tube, Forging, Wire
Available Forms
Nitriding steel that develops an extremely hard, wear- and corrosion-resistant surface after nitriding with minimal distortion. Aluminium (≈1%) forms hard AlN nitrides, giving the highest surface hardness. Used for crankshafts, cylinder liners, screws, valves, die blocks and precision machine components.
Uses
Austenitize at 820–870 °C (oil or water quench depending on section) and temper at 400–650 °C to the required strength/toughness balance. Quench & temper first to ≈30–40 HRC, then gas/nitride at 480–540 °C for 10–60 h; no further quench needed — minimal distortion.
Heat Treatment
Preheat and control interpass temperature when welding; post-weld heat treatment or stress relief is recommended to avoid hard-zone cracking. Use low-hydrogen electrodes. Protect from decarburization during heating (controlled atmosphere or protective coating). Machine the core stock before surface hardening; leave grinding allowance for the hardened case.
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