Material Name: cutting structural steel
Grade: Y20
Standard: GB / T 8731-1988
● Features and application:
Low parathion composite free cutting steel, the cutting is better than steel and less than 20 Y12 steel, but higher than the Y12 Y20 mechanical properties of steel. Cutting after forming can be carburized, used to make a hard surface, the center of the instrument parts toughness and high wear-resistant shaft parts.
● Chemical Composition:
Carbon C: 0.17 ~ 0.25
Si Si: 0.15 ~ 0.35
Manganese Mn: 0.70 ~ 1.00
Sulfur S: 0.08 ~ 0.15
Phosphorus P: ≤ 0.06
● Mechanical Properties:
Tensile strength σb (MPa): (hot) 450 ~ 600; (cold drawn) steel thickness or diameter of 8 to 20 hours: 570 ~ 785;> 20 to 30 hours: 530 ~ 745;> 30 hours: 510 ~ 705
Elongation δ5 (%):( hot) ≥ 20; (cold) ≥ 7.0
Reduction of ψ (%):( hot) ≥ 30
Hardness: (hot) ≤ 175HB; (cold drawing) 167 ~ 217HB
● Heat treatment and microstructure specifications:
● Delivery status: the hot-rolled or cold-drawn state of delivery, delivery status should be indicated in the contract