Spring steel refers to steel specially used to manufacture springs and elastic elements because of its elasticity under quenching and tempering [SCALE STEEL]conditions.The elasticity of a steel depends on its ability to elastically deform, that is, to withstand a certain load within a specified range without permanent deformation after the load is removed.
65Mn is a typical spring steel with high strength, high hardenability, low decarburization tendency, but it is sensitive to overheating, easy to produce [SCALE STEEL]quenching cracks and temper brittleness.Its cutting performance is also good, in the annealing state, the relative machinability of 70%.
As low manganese spring steel (GB/T 1222), 65Mn is used for manufacturing large flat spring, cushion spring, spring spring, also suitable for manufacturing [SCALE STEEL]spring ring, valve spring, clutch spring, brake spring cold drawn wire (≤7mm), cold coil spring, etc.
High elastic limit, yield strength and fatigue strength, and high hardenability, good cutting characteristics, also makes 65Mn become the main material for[SCALE STEEL] manufacturing diamond circular saw blade.
In addition to the use of spring, 65Mn is another identity of carbon structural steel (GB/T 699), used in the field of machine processing, is a typical [SCALE STEEL]material of cold work die steel, among which round steel is the most widely used field.
STANDARDS GB/T 1222 ASTM A689
GRADES 65Mn 1566
C 0.62~0.70 0.60~0.71
Si 0.17~0.37 --
Mn 0.90~1.20 0.85~1.15
P ≤0.035[SCALE STEEL] ≤0.040
S ≤0.035 ≤0.050
Cr ≤0.25 --
Ni ≤0.25 --
Cu ≤0.25 --
MECHANICAL PROPERTY（GB/T 1222-2007）
SAMPLE SIZE（mm） 10
HEAT TREATMENT QUENCHING TEM 830℃
QUENCHING MEDIUM MEDIA OIL
TEMPERING TEM 540℃
MECHANICAL PROPERTY TENSILE STRENGTH MPa[SCALE STEEL] ≥980
YIELD STRENGTH MPa ≥785
ELONGATION % ≥8
REDUCTION OF AREA % ≥30
HBW HOT ROLLED ≤302
COLD BEND + HEAT TREATMENT ≤321