2015-11-21 09:16:59 Origin： Remark：0 Click：
MATERIAL TECHNICAL DATASHEET - Grade DIN 55Si7
MATERIAL TYPE: Spring Steel
MATERIAL STANDARDS: DIN 17221
CHEMICAL COMPOSITION (Mass weight - %)
C (％): 0.52 ~ 0.60
Si (％): 1.60 ~ 2.00
Mn (％): 0.60 ~ 0.90
P (％)≤: 0.025
S (％)≤: 0.025
Cr (%): ≤ 0.40
Mo (%): ≤ 0.10
V (%): -
Other(％): Ni ≤0.40, Cu + 10Sn +/- 0.60
MECHANICAL PROPERTIES UNDER ROOM TEMP.
Range of size/mm|flat bar: 18
Range of size/mm|round bar: -
Mechanical property ≥|σb/MPa: 1470～1670
Mechanical property ≥|σs/MPa: 1080
Mechanical property ≥|δ5(%): 6
Mechanical property ≥|ψ(%): 25
Mechanical property ≥|Akv /J: 14
HOT WORKING & HEAT TREATMENT
Hot working temperature /℃: 1050~850
Thermal forming temperature /℃: 900~830
Heat treatment temperature/℃|annealing /℃: 640～680
Heat treatment temperature/℃|normalizing /℃: 850~880
Heat treatment temperature/℃|quenching /℃: 820～870 Oil
Heat treatment temperature/℃|tempering /℃: 430～500
Hardness after annealing ≤HBW: 235
MAIN FEATURES & PERFORMANCE REQUIREMENTS
Spring steel is specialized in producing the spring and elastic components due to its elasticity under the condition of quenching and tempering. The elasticity of steel depends on its capacity of elastic deformation.
This allows objects made of spring steel to return to their original shape despite significant bending or twisting occurs.
Spriing steel should possess excellent combination property, such as mechanical property (limit of elasticity, ultimate strength, yield ratio), relaxation resistant, fatigue property, hardenability, physical and chemical property (heat resistance,low temperature resistant, antioxidation, corrosion resistance). To meet the above performance requirement, Spring steel has fine metallurgical quality ( high purity, homogeneity), excellent surface quality ( specially on surface defect and decarburization), precise external form and dimensions.
Spring Steel requires higher strength and fatigue limit, usage in the condition of quenching + mesothermal tempering, then it can get higher elastic limit. Process engineering of heat treatment is very important to inherent quality of spring steel.
General spring steels are produced in electric furnace, open hearth furnace, oxygen converter,and high quality spring steel of higher quality or special performance can be made in electro slag furnace or vacuum furnace.
Spring Steel is commonly used in the condition of impact, vibration, or long-term stress. which makes the spring steel require higher tensile strength, limit of elasticity, fatigue strength. also requirement of definite hardenability, good surface quality, not easy decarburization.
PRODUCT PROFILE / DIMENSION
Round bar / Wire rod (Diameter): 5.5mm to 500mm
Square bar / Flat bar: 10mm to 800mm
Length: Fixed length or random length or based on the customer's special requirement.
Heavy/middle plate via hot rolled: T60 - 400mm X W10 - 1000mm X L1000 - 4000mm
Forging piece: stepped shafts with flanks / discs /tubes /slugs /donuts /cubes /other different shapes based on OEM.
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