Stainless Steel Grade AISI 416Se

AISI 416Se is a martensitic stainless steel that, due to the selenium (Se) and sulfur (S) content, provides better machinability than other similar stainless steels. However, this inclusion reduces the weldability, formability and corrosion resistance of this grade to a level lower than that of AISI 410.

Despite this, the AISI 416 Se grade has a fairly high resistance to acids, alkalis and dry air.

This is one of the most widely used dispersion hardening grades in industry. Despite the fact that the metal of this grade is soft and plastic in the solution annealing state, it is capable of acquiring high properties after a single precipitation or aging treatment. It is characterized by fairly good corrosion resistance, high hardness, viscosity and strength.

Machinability

Long sticky chips characterize the machinability of this metal. It can be machined in an annealed condition, but the best results are obtained in the H1150M condition. When machining under these conditions, the parts should be treated with a solution after machining before final hardening.

Welding

AISI 416Se steel is poorly welded. The weldability is affected by the high sulfur content in its composition. If possible, it is better to avoid welding this grade. If welding cannot be avoided, filler EN 1.4833 should be used. Quenching at 650 °C after welding is recommended to restore some plasticity in the welding and heating zone.

Forging

Before forging, hold for 1 hour at 1177 °C. Do not work at temperatures below 1010 °C. After-work treatment with a solution is required before final hardening.

Heat treatment

1. Conditions A. Hold at 1038 °C for 30 minutes and cool to below 16 °C for complete martensitic transformation.
2. Condition H950 - treatment of material in condition A at a temperature of 482 °C for 1 hour, cooling in air.
3. Condition H925, H1025, H1075, H1100, H1150 - soaking the material treated with the solution for 4 hours at the specified temperature, cooling in air.
4. Condition H1150M - soak solution treated material at 760 °C for 2 hours, air cool, then reheat to 620 °C for 4 hours and air cool.