2023-11-09 14:39
(supersedes all previous editions)
Alleima® 19C27 is a martensitic stainless chromium steel with high carbon content. After heat treatment the grade is characterized by:
Alleima® 19C27 is mainly used for industrial knives for cutting synthetic fibre, paper and plastic films.
C | Si | Mn | P | S | Cr |
---|---|---|---|---|---|
0.95 | 0.4 | 0.7 | ≤0.025 | ≤0.010 | 13.5 |
The strips can be supplied either in coils or as straightened lengths of 0.5-4.0 meter (1.6-13.1 feet). The coil weight is max. 5 kg/mm (280 lbs/in.) of strip width.
Hardening and tempering of the strip steel is needed to achieve the correct finish and to meet the properties required by the end user.
Thickness | Width | ||
---|---|---|---|
mm (in.) | mm (in.) | ||
Min. | Max | Min. | Max. |
0.1 (0.0039) | 3.0 (0.118) | 5 (0.197) | 340 (13.39) |
Other sizes can be supplied to meet specific requirements.
The thickness and width tolerances are +/- tolerances to the nominal size. The normal tolerance classes for most of our strip products are T2 and B1. Tighter tolerances as well as other tolerance limits can be offered upon request.
As-delivered | Tensile strength | Hardness | HRB |
---|---|---|---|
MPa (ksi) | HV | ||
Annealed |
max. 800 (116)
|
max. 275 | max 103 |
Cold rolled |
850-1000 (123-160)
|
265-345 | 101.4-108.7 |
Hardening temperature 1060°C (1940°F), strip thickness 1.0 mm (0.039 in.), holding time 3 minutes, quenching in oil.
Tempering time 30 minutes.
Brittleness occurs with tempering above 450°C (840°F).
Additional recommendations regarding hardening can be found in Alleima's hardening guide.
The following figures show the importance of using the right hardening conditions to optimize the microstructure and properties.
Too high hardening temperature gives coarse structure, high austenite content (30%), few carbides. Consequence: low hardness and bad wear resistance.
Too low cooling rate after austenitizing gives carbide precipitations in the grain boundaries. Consequence: brittleness and reduced corrosion resistance.
Optimized hardening conditions give optimal austenite content (15%), many uniformly distributed carbides. Consequence: optimal combination of hardness, wear resistance, ductility and corrosion resistance.
Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.