The material use of T7 steel, the physical properties of T7 steel

The physical properties of T7 steel are shown in Table 2-20-2 Table 2-20-4, and its density is; Magnetic permeability approximately; The coercivity HC was 318 954A m (the lower limit of HC was suitable for spheroid tissue, and the upper limit was suitable for pearlite tissue; Saturated magnetic inductance BS is; Resistivity is.

Table 2-20-2 Critical temperature of T7 steel Critical point AC1 AC3 AR1 Temperature (approximate) 730 770 700 Table 2-20-3 Linear (expansion) coefficient of T7 steel Temperature 20 100 20 200 20 300 20 400 Linear (expansion) expansion coefficient -1 Table 2-20-4 Thermal conductivity of T7 steel Temperature 20 100 300 Thermal conductivity w·(m·k)-1

T7 belongs to carbon tool steel, while 70 belongs to high-quality carbon structural steel strip, which is different in use.

In addition to carbon, in addition to the composition, it is also different, in order to reduce the cold brittleness of the tool steel, the hot brittleness so the content of sulfur and phosphorus elements is lower.

Hello, after inquiry, T7 and T8 indicate carbon content T7 and T8 steel, which are used to make tools with high toughness, such as punches, chisels, etc.

In addition, there are T9, T10, T11 steels, which are used as cutting tools that require medium toughness and high hardness, such as drill bits, taps, saw blades, etc. T12 and T13 steels are used for files and wire drawing dies that require higher hardness and high wear resistance.

What do t7 and t8 mean in materials?

Hello, after inquiry, T7 and T8 indicate carbon content T7 and T8 steel, which are used to make tools with high toughness, such as punches, chisels, etc.

In addition, there are T9, T10, T11 steels, which are used as cutting tools that require medium toughness and high hardness, such as drill bits, taps, saw blades, etc. T12 and T13 steels are used for files and wire drawing dies that require higher hardness and high wear resistance.

Here 8 means the carbon content is.

T7A is a type of carbon tool steel. The steel has good toughness, good chip machinability, low and easy, low hardenability and wear resistance, weak cavity shrinkage tendency during quenching, large quenching deformation, poor tempering stability, and the hardening depth is 15-18mm for water quenching and 5-7mm for oil quenching. It is suitable for making small pieces that are easy to quench, and large pieces are prone to arc cracks due to the shallow hardening layer.

Chemical composition. Mass Fraction %

Performance characteristics: It has good toughness and hardness, but the machinability is poor and the strength is low. Delivery condition is annealed or high temperature tempered (plate thickness).

Scope of use: Suitable for manufacturing requiring appropriate hardness. A variety of tool steels that can withstand impact loads and have good toughness.

T7 steel has good toughness and hardness, but poor cutting ability; It is mostly used to make tools that need to have greater toughness and a certain hardness, but the cutting capacity is not very high.