Detailed description

1.Characteristics and application:

Compared with steel NO.30, the intensity and its quench-hardening ability are high, the steel usually in conditioning state use, also can use in is after the fire. Used as in the wear and tear of impact load of the major parts work, such as the axis, small shaft, balance lever, rocker, connecting rod, bolts, nuts, gear and all kinds of roller, etc.; Also used for need to the surface of the quenching process parts.

2.Chemical ingredients:

C: 0.24 ~ 0.31Si: >0.40Mn: 0.60 ~ 0.90S: allow residual content than 0.035P: allow residual content than 0.035Cr: 0.90 ~ 1.20Ni: allow residual content than 0.25 copper Cu: allow residual content than 0.030

3.Mechanical properties:

Tensile strength σ b (MPa) : frequency 885 (90)The yield strength σ s (MPa) : frequency 685 (70)Elongation δ 5 (%) : 11 frequencyArea reduction ψ (%) : 45 frequencyImpact energy Akv (J) : 47 frequencyImpact toughness values α kv (J/cm2) : 59 quartile (6)Hardness: more than 187 HBSample size: sample blank dimensions for 25 mm

4.Heat treatment standard and metallographic organization:

Heat treatment specification: quenching 860 °C, the oil cold; Tempering 500 °C, water, oil, and cold.

5.Delivery status:

to heat treatment (is fire, annealed or high temperature tempering) or not heat treatment state delivery, delivery status should be indicated in the contract

28Cr4(1.7030) special steel