Mechanical properties and hardness of 27MnTiB alloy structural steel

27MnTiB alloy structural steel belongs to high-carbon boron-containing steel, which is mainly used to manufacture loader box and excavator bucket. It needs to have good wear resistance and high hardness, and it is extremely difficult to smelt. It is precisely because of the high quality requirements of this type of steel that only a few domestic steel mills can produce it. At the same time, the steel grade also has a large market. 27MnTiB bucket steel has the characteristics of high precious alloy content, narrow composition control range, strong billet crack sensitivity, high molten steel purity, and is difficult to smelt.

27MnTiB alloy structural steel chemical composition:
Carbon C: 0.24-0.0.30
Silicon Si: 0.17-0.37
Manganese Mn: 1.30-1.60
The allowable residual content of sulfur S and phosphorus P is not higher than 0.035 respectively.
Chromium Cr, nickel Ni, copper Cu allowable residual content not higher than 0.030 respectively.
Titanium Ti: 0.04-0.10
Boron B: 0.0005-0.0035

Mechanical properties of 27MnTiB alloy steel:
Specimen blank specification (mm): 25
Tensile strength (σb/MPa): ≧980
Yield point (σs/MPa): ≧835
Elongation after break (δ5/%): ≧12
Section shortening rate (ψ/%): ≧40
Shock absorption energy (Aku2/J): ≧39
Brinell hardness (HBS100/3000) (annealed or tempered at high temperature): ≦217

27MnTiB alloy structural steel heat treatment method:
Primary quenching heating temperature (℃): 920; coolant: water
2nd quenching heating temperature (℃):-
Tempering heating temperature (℃): 450; coolant: water, oil