About
Hite Special Alloy is a high-tech enterprise, mainly engaged in the production of Hastelloy, Monel, Inconel, nickel and other high-temperature alloys.
4J36 is a special low expansion iron-nickel alloy with ultra-low expansion coefficient. The control of carbon and manganese components is very important. Cold deformation can reduce the coefficient of thermal expansion, and 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 (rust) may occur.
High energy beam welding High energy beam welding of superalloys mainly includes laser welding and electron beam welding. These two methods have the advantages of small heating range, large penetration depth, and small welding deformation. However, their high welding energy and large temperature gradient may cause large local residual stresses, and are prone to cause welding thermal cracks during the welding process. The microstructure and weld zone composition of laser welded joint of nickel based cast superalloy K418 were studied, and the causes of joint cracks were analyzed. The results show that the metal vapor and plasma generated during laser welding lead to the appearance of large nail heads and small nail bodies in the weld seam; The microstructure of the weld near the base metal is a dendritic structure; The elements phosphorus, sulfur, and silicon form low melting point compounds at the grain boundaries, increasing thermal cracking sensitivity. Laser welding of nickel based superalloys was carried out, and the causes of thermal cracks in the weld and weld heat affected zone were discussed.
4J36 alloy, also known as INVAR alloy, has a Curie point of about 230 ℃. Below this temperature, the alloy is ferromagnetic and has a very low coefficient of expansion. Above this temperature, the alloy is nonmagnetic and has an increased coefficient of expansion. This alloy is mainly used for manufacturing components with approximately constant dimensions within the temperature range, and is widely used in the radio industry, precision instruments, meters, and other industries.
Process performance and requirements of 4J36:
1. Alloys are easily cold and hot worked. During hot processing, heating in a sulfur containing atmosphere should be avoided.
2. The cutting characteristics of this alloy are similar to those of austenitic stainless steel. When machining, high-speed steel or cemented carbide cutters are used for low-speed cutting. Coolant can be used during cutting. The alloy has good grinding performance.
