The tested steel 0Cr17Ni4Cu4Nb (/%: 0.016~0.017C

0.31~0.35Si

0.79~0.85Mn

0.009~0.012P

0.008~0.010S

15.29~15.43Cr

4.10~4.15Ni

3.34~4.92Cu

0.25~0.27Nb) is melted by a 25kg vacuum induction furnace and forged to Φ18mm bar. The 3.34%~4.92% Cu content on phase transformation point of steel 0Cr17Ni4Cu4Nb

mechanical properties and structure of steel oil-quenched at 1040°C for 1h and oil-cooling aged at 460~610°C for 2h is tested and studied by mechanical properties measurement and structure analysis. Results show that with increasing Cu content in steel the effect of Cu content on Ac

3

is not obvious but the Ac

1

decreases in some extent

and the M

s

point of steel moves up

while the M

f

point of steel comes down；with higher Cu content in steel the strength and hardness of steel is higher

but plasticity of steel is slightly lower；with control the Cu content in steel being minimum to middle of standard permissible variations

it is able to meet the mechanical properties requirement of specification

i. e. with aged at 460~500℃ the steel R

m

≥1315MPa

R

p0.2

≥1175MPa

A≥10% and Z≥40%.