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4J36 precision alloy plate Invar 36 alloy steel plate 1250mm for pharmaceutical equipment
4J36 is a special low expansion iron nickel alloy with an ultra-low coefficient of expansion. The control of carbon and manganese components is very important. Cold deformation can reduce the coefficient of thermal expansion, while heat treatment within a specific temperature range can stabilize the coefficient of thermal expansion. 4J36 has corrosion resistance in dry air at room temperature. In other harsh environments, such as humid air, corrosion (rusting) may occur.
Chemical composition and physical properties
The main chemical components of 4J36 alloy include iron, nickel,
and cobalt, with nickel content typically ranging from 35.0% to
37.0%, iron as the balance, and cobalt content generally not
exceeding 0.5%. In addition, it also contains small amounts of
elements such as manganese (Mn), chromium (Cr), silicon (Si),
carbon (C), phosphorus (P), and sulfur (S). Within the temperature
range of -100 ° C to 200 ° C, its average coefficient of linear
expansion is approximately 1.2 x 10 ^ -6/° C, exhibiting extremely
low thermal expansion characteristics.
Normal composition%
Ni | 35~37.0 | Fe | Bal. | Co | - | Si | ≤0.3 |
Mo | - | Cu | - | Cr | - | Mn | 0.2~0.6 |
C | ≤0.05 | P | ≤0.02 | S | ≤0.02 |
Typical Physical properties
Density (g/cm3) | 8.1 |
Electrical resistivity at 20℃(Ωmm2/m) | 0.78 |
Temperature factor of resistivity(20℃~200℃)X10-6/℃ | 3.7~3.9 |
Thermal conductivity, λ/ W/(m*℃) | 11 |
Curie point Tc/ ℃ | 230 |
Elastic Modulus, E/ Gpa | 144 |
Mechanical performance
4J36 alloy has high tensile strength and yield strength, ranging
from 490 to 680 MPa and ≥ 240 MPa, respectively. Its elongation
rate is between 25% and 35%, and its hardness is 130 to 180 HB in
the annealed state, and higher at 170 to 200 HB in the cold-rolled
state. These excellent mechanical properties enable 4J36 alloy to
withstand significant external forces and deformations, thereby
maintaining stable performance in various applications.
Heat treatment process
The heat treatment process of 4J36 has a significant impact on its
performance, mainly including the following steps:
Homogenization treatment: Heat the alloy to a temperature slightly
above its solution line temperature and maintain it for a period of
time to ensure uniform distribution of alloy components. This step
helps to eliminate segregation and stress that may occur during
casting or forging processes.
Rapid cooling: After homogenization treatment, the alloy is rapidly cooled to room temperature or slightly lower to preserve the microstructure of the solid solution. This step is commonly referred to as quenching or rapid cooling.
Aging treatment: In order to obtain the desired properties of the alloy, it is usually necessary to perform aging treatment at a lower temperature. The temperature and time for aging treatment depend on specific application requirements and the composition of the alloy. By aging treatment, the microstructure of the alloy can be adjusted, thereby improving its mechanical properties and stability.
Annealing treatment (optional): In some cases, annealing treatment may be necessary to further reduce the hardness of the alloy and improve its toughness. Annealing treatment usually involves heating at a lower temperature for a long time and then slowly cooling to room temperature.
application area
4J36 alloy has demonstrated extensive application value in multiple
fields:
Precision manufacturing: used for manufacturing precision
instruments and meters that require precise dimensions to be
maintained under temperature changes, such as sensors, standard
measuring tools, measuring instruments, etc.
Electronic packaging: Due to its low coefficient of expansion and
good weldability, it is commonly used for packaging and connecting
electronic components.
Aerospace: In aerospace vehicles, 4J36 alloy can effectively solve
the dimensional stability problem caused by temperature changes,
ensuring tight connections and stable operation of key components.
Optical instruments: Used in optical instruments, precision
measuring instruments, and precision machinery to manufacture
various key components such as lens holders, barrels, mirror
support frames, etc., to ensure the accuracy and stability of the
instruments.
Similar grades of 4J36 include Fe-Ni36 (France), W.Nr.1.3912
(Germany), Ni36 (Germany), X1NiCrMoCu, N 25-20-7 (UK), and
UNSK93600 thermostat alloy (USA).
In summary, 4J36, as an expansion alloy with excellent dimensional
stability, occupies an important position in the field of materials
science. Its unique performance advantages have demonstrated
enormous application potential in multiple high-tech fields.
corrosion prevention
4J36 alloy has corrosion resistance in dry air at room temperature.
However, in humid or harsh environments, its corrosion resistance
may decrease, so additional protective measures need to be taken,
such as coating with anti rust paint or passivation treatment.
Welding performance
4J36 alloy can be welded using all welding processes, including
tungsten electrode welding, metal arc welding, plasma welding,
argon arc welding, manual arc welding, etc. Before welding, the
material should be in an annealed state, clean, free of oil stains,
scratches, marking paint, etc. Low heat input must be used, and the
interlayer temperature should be below 120 ℃. No pre weld and post
weld heat treatment is required. If the weld performance is
designed to be the same as the base metal, it is necessary to use
welding rods of the same material as the base metal.
summary
4J36 (Kovar alloy wire), as a metal alloy material with unique
properties, has been widely used in various fields such as
aerospace, electronic communication, and precision instruments. Its
excellent performance and wide application prospects make it play
an important role in the field of metal materials. In the future,
with the continuous optimization of preparation processes and the
continuous improvement of performance, 4J36 alloy will be applied
in more fields and provide strong support for the development of
related industries.