trademark: 30Cr ASTM 5130 28Cr4 1.7030
standard:GB/T 3077-1999
features and use scope:
It has high intensity and hardenability than steel of number 30 .It always uses in tempering and also uses after normalizing .It used to making parts of abrasion and big burthen concussion ,such as axis ,staff,equalizer beam,rocker,connecting rod,bolt ,gear and all kinds of roller and so on .It also uses to the parts which after quenching on the face.

Chemical composition:
C :0.27~0.34
Si:0.17~0.37
Mn:0.50~0.80
S :allow remains content≤0.035
P :allow remains content≤0.035
Cr:0.80~1.10
Ni:allow remains content≤0.030
Cu:allow remains content≤0.030
mechanical properties:
tensile strength σb (MPa):≥885(90)
yield strength σs (MPa):≥685(70)
extensibility δ5 (%):≥11
reduction of area ψ (%):≥45
ballistic work Akv (J):≥47
notched bar impact strength αkv (J/cm2):≥59(6)
rigidity :≤187HB
specimen size:specimen size of rough 25mm
heat treatment regime and metallurgical structure:
heat treatment regime :quenching 860℃,oil cooling ;backfire 500℃,water cooling \oil cooling .
deliver position :heat treatment(normalizing\annealing or high-temperature backfire)or no heat treatment,this should be shown on the contract.