ASTM A 335/A 335M Seamless Alloy Steel Pipes 01

Hebei Metals Industrial Limited supplies seamless ferritic alloy steel pipes for high temperature services in accordance with ASTM A 335/A 335M. ASTM A 335 alloy steel pipes are widely used in high temperature service, such as heat exchangers, furnace tubes, high-pressure steam lines and chemical reactor vessels, etc.

Alloy steels conforming to this standard are usually called as "Cr-Mo" alloy steels which contain deliberate amounts of specific alloying elements: chromium(Cr) and Molybdenum(Mo). For example, the ASTM A 335 seamless pipes can be categorized as 0.5Cr-0.5Mo (ASTM A 335 P2), 1Cr-0.5Mo (ASTM A 335 P12), 1.5Cr-0.5Mo (ASTM A 335 P11), 2Cr-1Mo(ASTM A 335 P3b), 2.25Cr-1Mo (ASTM A 335 P22), 3Cr-1Mo (ASTM A 335 P21), etc. Intermediate alloy steels contain between 3% and 10% Cr, such as 4 to 9Cr ~ 0.5 to 1Mo (ASTM A 335 P5 to P9). Chromium increases resistance to abrasion and wear as well as improves resistance to high temperature hydrogen attack and graphitization. Molybdenum is is a grain refiner. It enhances creep resistance and high temperature strength. It improves resistance to pitting corrosion in many environments.

1. Chemical Requirements of ASTM A 335 Alloy Steel Pipes

Grade	UNS	CHEMICAL REQUIREMENTS
Grade	UNS	C	Mn	P	S	Si	Cr	Mo	Others
P1	K11522	0.10~0.20	0.30~0.80	0.025	0.025	0.10~0.50	-	0.44~0.65	-
P2	K11547	0.10~0.20	0.30~0.61	0.025	0.025	0.10~0.30	0.50~0.81	0.44~0.65	-
P5	K41545	0.15	0.30~0.60	0.025	0.025	0.50	4.00~6.00	0.45~0.65	-
P5b	K51545	0.15	0.30~0.60	0.025	0.025	1.00~2.00	4.00~6.00	0.45~0.65	-
P5c	K41245	0.12	0.30~0.60	0.025	0.025	0.50	4.00~6.00	0.45~0.65	*A
P9	S50400	0.15	0.30~0.60	0.025	0.025	0.25~1.00	8.00~10.00	0.90~1.10	-
P11	K11597	0.05~0.15	0.30~0.60	0.025	0.025	0.50~1.00	1.00~1.50	0.44~0.65	-
P12	K11562	0.05~0.15	0.30~0.61	0.025	0.025	0.50	0.80~1.25	0.44~0.65	-
P15	K11578	0.05~0.15	0.30~0.60	0.025	0.025	1.15~1.65	-	0.44~0.65	-
P21	K31545	0.05~0.15	0.30~0.60	0.025	0.025	0.50	2.65~3.35	0.80~1.06	-
P22	K21590	0.05~0.15	0.30~0.60	0.025	0.025	0.50	1.90~2.60	0.87~1.13	-
P23	K41650	0.04~0.10	0.10~0.60	0.030	0.010	0.50	1.90~2.60	0.05~0.30	*B
P91	K91560	0.08~0.12	0.30~0.60	0.020	0.010	0.20~0.50	8.00~9.50	0.85~1.05	*C
P92	K92460	0.07~0.13	0.30~0.60	0.020	0.010	0.50	8.50~9.50	0.30~0.60	*D
P122	K92930	0.07~0.14	0.70	0.020	0.010	0.50	10.00~12.50	0.25~0.60	*E
P911	K91061	0.09~0.13	0.30~0.60	0.020	0.010	0.10~0.50	8.50~10.50	0.90~1.10	*F

*A Grade P5c shall have a titanium content of not less than 4 times the carbon content and

not more than 0.70%; or a columbium content of 8 to 10 times the carbon content.

*B V: 0.20~0.30; Cb 0.02~0.08; B: 0.0005~0.006; N: 0.030 max; Al: 0.030 max;

W: 1.45~1.75

*C V: 0.18~0.25; N: 0.030~0.070; Ni: 0.40 max; Al: 0.04 max; Cb: 0.06~0.10

*D V: 0.15~0.25; N: 0.03~0.07; Ni: 0.40 max; Al: 0.04 max; Cb: 0.04~0.09; W: 1.5~2.00;

B: 0.001~0.006

*E V: 0.15~0.30; W: 1.50~2.50; Cu: 0.30~1.70; Cb: 0.04~0.10; B: 0.0005~0.005;

Ni: 0.50 max; Al: 0.040 max

*F V: 0.18~0.25; Ni: 0.40 max; Cb: 0.060~0.10; B: 0.0003~0.006; N: 0.04~0.09;

Al: 0.04 max; W: 0.90~1.10

2. Mechanical Properties of ASTM A 335 Alloy Steel Pipes

Grade	UNS	Tensile Strength (min.)		Yield Strength (min.)		*Elongation % (min.)
Grade	UNS	ksi	MPa	ksi	MPa	Longitudinal	Transverse
P1	K11522	55	380	30	205	30	20
P2	K11547	55	380	30	205	30	20
P5	K41545	60	415	30	205	30	20
P5b	K51545	60	415	30	205	30	20
P5c	K41245	60	415	30	205	30	20
P9	S50400	60	415	30	205	30	20
P11	K11597	60	415	30	205	30	20
P12	K11562	60	415	32	220	30	20
P15	K11578	60	415	30	205	30	20
P21	K31545	60	415	30	205	30	20
P22	K21590	60	415	30	205	30	20
P23	K41650	74	510	58	400	20	-
P91	K91560	85	585	60	415	20	-
P92	K92460	90	620	64	440	20	-
P122	K92930	90	620	58	400	20	-
P911	K91061	90	620	64	440	20	-

*Basic elongation for wall 5/16"(8mm) and over in thickness, strip tests, and for all small

sizes tested in full section. Contact us to get the computed minimum elongation values for

each 1/32"(0.8 mm) decrease in wall thickness.

*Seamless pipes of Grades P91, P92 and P122 shall have a hardness not exceeding 250 HB /265 HV (25 HRC).

Views: Author：hbmetals Date:15/07/14