High Strength 4J33 4J335 Steel Ingot 1J117 Hot Rolled Forged Rod 33HK Round

Product Specification

4J33 4J335 steel ingot 1J117 hot rolled forged bar 33HK round steel plate custom processing Ni33Co17.

4J33 (Expansion Alloy Round Steel)

4J33 is an iron-nickel-cobalt alloy with a specific expansion coefficient, also known as expansion alloy round steel. It has been widely used in precision instruments, electronic devices, aerospace and other fields due to its unique thermal expansion properties.

The linear expansion coefficient of this alloy matches that of certain ceramic materials, glass, etc. when the temperature changes, which makes 4J33 an ideal material for manufacturing precision sealing structures. For example, in vacuum electronic devices, 4J33 alloy is often used to seal with glass to ensure the airtightness and stability of the device.

In addition, 4J33 alloy also has good mechanical properties and processing properties. It can be made into parts of various shapes and sizes, such as round steel, plates, strips, etc., through processes such as cold drawing, cold heading, and hot rolling. These parts can maintain high dimensional accuracy and surface quality during the manufacturing process, thus meeting the needs of various complex structures.

Chemical composition and physical properties

The main chemical components of 4J33 alloy include nickel (Ni), cobalt (Co), iron (Fe), and a small amount of other elements such as silicon (Si), manganese (Mn), carbon (C), etc. Specifically, the chemical composition of 4J33 alloy is as follows:

‌Nickel (Ni) ‌: about 32.1%-33.6% ‌Cobalt (Co) ‌: about 14.0%-15.2% ‌Iron (Fe) ‌: balance ‌Carbon (C) ‌: ≤0.05% ‌Phosphorus (P) ‌: ≤0.020% ‌Sulfur (S) ‌: ≤0.020% ‌Manganese (Mn) ‌: ≤0.50% ‌Silicon (Si) ‌: ≤0.30% ‌These components make 4J33 alloy have low thermal expansion coefficient and excellent mechanical properties, widely used in the manufacture of electron tubes, magnetron electrodes, etc., and sealed with ceramics such as Al₂O₃.

In addition, 4J33 alloy also has good processability and welding performance, suitable for various mechanical processing and a variety of welding methods.
The main components of 4J33 round steel include iron (Fe), nickel (Ni), cobalt (Co) and a small amount of chromium (Cr), molybdenum (Mo) and other elements. Its chemical composition ratio is usually: nickel 32.1~33.6%, cobalt 14.0~15.2%, and the rest is iron and a small amount of impurity elements such as carbon, phosphorus, sulfur, manganese, silicon, etc. The thermal expansion coefficient of the alloy in the range of 20~100℃ is 6.5×10^-6/℃, and in the range of -60~600℃, its linear expansion coefficient is similar to that of 95% Al2O3 ceramics, which makes it often used for sealing with ceramics. In addition, the density of 4J33 alloy is about 8.5g/cm³ and the melting point is about 1390~1400℃.

Mechanical properties and processing properties
4J33 round steel has high strength, good plasticity and toughness. Its tensile strength and yield strength vary according to the specific heat treatment state, but it has high strength and hardness in general. At the same time, the alloy also exhibits good plastic deformation ability and has a high elongation. 4J33 alloy has good processing performance and weldability, and can be processed into various complex shapes through forging, rolling, drawing, stamping and other processes to meet diverse design requirements. During the processing, it is necessary to avoid heating in a sulfur-containing atmosphere and control the strain rate during cold processing to avoid the generation of plastic anisotropy.

Application field
4J33 round steel has been widely used in many fields due to its unique properties:

Aerospace: used to manufacture structural components in high temperature environments, such as aircraft parts, satellite brackets, etc.

Electronic communication: used to manufacture sealing, lead wires and structural materials, widely used in vacuum devices such as electron tubes, transistors, integrated circuits, etc.

Precision instruments and meters: used to manufacture key components such as precision shafts, lens barrels, reflector seats, etc. to ensure the accuracy and stability of the instrument.

Energy field: used to manufacture control rods and pressure vessels in nuclear reactors, as well as absorbers and collectors in solar thermal utilization systems.
‌Medical equipment‌: used to manufacture electromagnetic components that require high precision and stability, such as magnetic cores, magnetic rings, etc. ‌Chemical and marine environments‌: Due to its excellent corrosion resistance, it is suitable for long-term work in a variety of corrosive environments‌.