1.4125 Stainless Steel | AISI 440B/AISI 440C | X105CrMo17/X90CrMoV18 | SUS440B/SUS440C | 95Cr18

1.4125 Stainless Steel | AISI 440B/AISI 440C | X105CrMo17/X90CrMoV18 | SUS440B/SUS440C | 95Cr18

1.4125 (X105CrMo17) steel is a martensitic stainless steel with high levels of corrosion and wear resistance. The 1.4125 (X105CrMo17) material provides high-temperature resistance and wear resistance, and its high hardness and sharpness characteristics make it ideal for cutting operations.

Chemical Composition

Mechanical Properties

Physical Properties

Weldability

If welding is necessary pre-heat at 250°C and follow welding with a full anneal. Grade 420 filler will give a high hardness weld (although not as high as the 440C), but 309 or 310 will produce soft welds with higher ductility.

Machinability

In the annealed condition this grade is relatively easily machined; approximately the same as for high speed steel. Chips are tough and stringy so chip breakers are important. If these grades are hardened machining becomes more difficult and probably impossible.

Corrosion Resistance

Good resistance to the atmosphere, fresh water, foods, alkalies and mild acids. Best resistance in the hardened and tempered and passivated condition. A smooth polished surface also assists.

The corrosion resistance of grade 440C approximates that of grade 304 in many environments.

Heat Treatment

· Annealing-Full anneal: 850-900°C, slow furnace cool to about 600°C and then air cool.

· Sub critical Annealing: 735-785°C and slow furnace cool.

· Hardening: Heat to 1010-1065°C, followed by quenching in warm oil or air. Oil quenching is necessary for heavy sections. Immediately temper at 150-370°C to obtain a wide variety of hardness values and mechanical properties as indicated in the accompanying table.

· Tempering in the range 425-565°C is to be avoided because of reduced impact resistance and corrosion resistance. Tempering in the range 590-675°C results in lower hardness (the product become machinable) and high impact resistance.

Applications

· Rolling element bearings

· Valve seats

· High quality knife blades

· Surgical instruments

· Chisels