1.chemical composition(m%):

Grade	C	Si	Mn	Cr	Mo	P	S
15Cr2Mo	0.12-0.18	0.17-0.37	0.40-0.70	2.30-2.60	0.40-0.55	≤0.009	≤0.009
21CrMo10	0.16-0.23	0.20-0.40	0.20-0.40	2.20-2.60	0.30-0.50	≤0.009	≤0.009
30CrMo	0.17-0.39	0.17-0.37	0.40-0.70	0.80-1.10	0.15-0.25	≤0.009	≤0.009

 2.mechanical property

Grade	Rm(MPa)	Rp0.2(MPa)	A(%)	Z(%)	Ak(j)	HBW
15Cr2Mo	≥780	≥680	≥12	≥50	≥78	≥230
21CrMo10	≥780	≥650	≥16	≥60	≥78	≥240
30CrMo	≥780	≥680	≥10	≥35	≥21	≥200

3.service life for reference

specification	servicelife	specification	servicelife
DN80-DN100	≥4800	DN450	≥2000
DN150	≥4400	DN500	≥1880
DN200	≥4000	DN600	≥1600
DN250	≥3600	DN700	≥1400
DN300	≥2600	DN800	≥1200
DN350	≥2400	DN900-DN1200	≥1000
DN400	≥2000