Steel 52100

Steel 52100 or Carbon steel 52100,chrome high steel content, is mainly used in the field of cutlery and for tools that require high mechanical strength.

Many know it because it is the material often used for bearings, piston pins etc .. it has 1% carbon and 1.5-1.6% Chromium, plus a little manganese and a little silicon.

You can also find it with the abbreviation 100Cr6 (DIN)

100Cr6 is currently the standard steel for rolling bearing balls, being used in more than 90% of cases, due to its properties:

• very high resistance to adhesive wear, thanks also to lubrication;
• resistance to abrasive wear, given by the low non-metallic inclusions and the uniformity in the distribution of hard carbides, which grind any inclusions;
• fatigue resistance thanks to the homogeneity of the structure: the steel can be hardened up to the heart thanks to the presence of chromium.

It is a martensitic steel.

This steel is also called AISI52100 in the Anglo-Saxon legislation.

It is a decidedly hypereutectoid steel: 1.5% chromium moves the eutectoid boundary curve to the left; containing 1% carbon, it should in fact if not be only slightly hypereutettoidic.

This characteristic must be kept in mind when choosing the hardening temperature: it is not advisable to exceed Ac_m (chromium enlarges the grain and austenite remains stabilized), while you choose to remain in the range γ + carbides (therefore 770-780 ° C).

So at the end of the hardening, which is usually in oil,the chromium carbides remain, inside the martensite, which make it necessary to have a tempering temperature of at least 220 ° C.

It is a steel with which you can get a spectacular mirror polishing.

Its main features:

• High hardness.
• High mechanical strength.
• High retention of the cutting edge.
• Up to 70 HRC.
• Very good mirror polished.
• Low oxidation.

Chemical composition (%):

C:1.00 Si:0.25 Mn:0.30 Cr: 1.50

Recommended this steel, both for beginners beginners and professionals, the degree of difficulty of the work is medium and comes supplied annealed (soft), to facilitate the work.

Heat treatment of steel 52100

– Forging : 850-1050°C. very slow cooling in the oven or insulation materials (mica salt, sand,).

– Normalization : 650°C. To eliminate structural stresses caused by forging or roughing. Preferred time, 1-2 hours.

– Tempered (oil) : 830 at 870°C. Slow and progressive heating, keep at least 1 minute per millimeter. Cooling in oil at 210-250°C to reduce thermal shock, keep cool for 15-20 minutes. Hardness HRC 63-66. To reach 67 HRC, hot water is recommended, with a temperature of 800 to 830 ° C.

– Tempering:from 150 to 250°C, for thicknesses up to 6 mm for 45 minutes. Slow heating to tempering temperature (see temperature table). Hardness 59-65 HRC.

Reclamation is recommended in a conservative atmosphere, see temperate blade.

This is the recommended heat treatment, there are others. Temperatures, timing or form of realization of it, depending on the needs you can vary or experience in such a process.

MATERIAL CUT MECHANICAL PROCESS MAY HAVE CURVES (NOT COMPLETELY FLAT).

Reference table for Steel 52100 ( AISI, ASTM, UNS) and its European equivalent 102Cr6 (1.2067) ( EN )

These acronyms are used to identify the same type of steel in the different countries of reference.