Determination of quenching heating and holding time. Quenching heating speed and quenching heating holding time are also two important parameters of quenching heating. For workpieces and large alloy steel forgings with complex shapes, small deformation or high-alloy steel, the heating speed must be limited to reduce quenching deformation and cracking tendency, while carbon steel and low-alloy steel with simple shapes can be heated quickly. The heating and holding time mainly depends on the thermal conductivity of the material itself, the shape and size of the workpiece, and the austenitization time, and also pays attention to the difficulty of dissolving carbides and alloying elements and the overheating tendency of the steel. The empirical formula for estimating the heating time is as follows:
t= akd
where t is the heating time (min).
a is the heating coefficient (min mm);
k is the furnace loading coefficient of the workpiece.
d is the effective thickness of the workpiece (mm).
The effective thickness of the workpiece is determined according to the following principle: the effective thickness of the shaft workpiece is its diameter;Plate or disc workpieces have their thickness as the effective thickness;If the inner hole of the sleeve workpiece is less than the wall thickness, the outer diameter shall be used as the effective thickness;If the inner hole is greater than the wall thickness, the wall thickness is the effective thickness;The conical workpiece takes the diameter from the small head 2 3 as the effective thickness, and the complex workpiece takes the size of its main working part as the effective thickness;The effective thickness of the workpiece is multiplied by the form factor of the workpiece to calculate the thickness.
n6
Material Grade:N6 pure nickel alloy
Commercial grade: Nickel 200
U.S. Grade:uns n0220
German Grade:
1. Overview of N6 (Nickel 200, N02200) pure nickel alloys:
The features of commercial pure nickel or low-alloy nickel are very useful in many fields, such as the chemical process and electronics industries. Nickel has some resistance to various reducing chemicals, while resistance to caustic alkali is irreplaceable. Compared with nickel-based alloys, commercial pure nickel has higher electrical and thermal conductivity, and at the same time, the Curie temperature is also higher, and it has good magnetostrictive properties. Annealed nickel has low hardness as well as good ductility and flexibility. These properties, combined with its good weldability, make the metal easy to machine and form. Nickel has a relatively low rate of work hardening, but it can be cold worked to achieve moderate strength levels and maintain its ductility.
N6 pure nickel alloy has good mechanical properties and excellent resistance in many corrosive environments. Other useful properties of the alloy include its magnetic properties, magnetostrictive properties, high thermal and electrical conductivity, low gas content and low evaporation pressure. The corrosion resistance of N6 makes it particularly useful in applications such as food, man-made fibers and caustic soda where product purity is required. It is also widely used in structural applications where corrosion resistance is a major consideration. Other uses include chemical drums, electrical and electronic components, aerospace and missile components.
2. N6 (nickel 200, N02200) pure nickel alloy: see Table 1:
Table-1
3. The main path of N6 (nickel 200, N02200) pure nickel alloy:
N6 pure nickel alloys have good mechanical properties at higher temperatures, however nickel 200 is generally limited to below 600°F (315°C). Nickel 200 products can be graphitized at high temperatures, which can severely degrade the performance of the product. When used above °F (315°C), nickel 201 is more commonly used. Pure nickel N6 and nickel N4 are approved structural materials for ASME boilers and pressure vessels**. N6 approved service temperatures up to 600°F (315°C) and N4 approved service temperatures up to 1250°F (677°C).
4. The main characteristics and applications of N6 (nickel 200, N02200) pure nickel alloys
1. N6 is pure commercial nickel with very low carbon content and has been approved for use in high-temperature environments up to 300 °C.
2. N6 application field:
1) Food processing equipment, salt refining equipment.
2) Mining and marine mining.
3) The equipment required to manufacture industrial sodium hydroxide under the high temperature condition below 300.
4) Production of organic or inorganic chlorides and fluorides: resistant to chlorine and fluoride corrosion.