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X60,X65,X70 and X80 Pipe Manufacturing exports,Techniques fo

Techniques for Welding High Strength Pipe

(X60, X65, X70 and X80 Pipe)

These recommendations are suggested to help produce crack-free welds with a minimum of defects on high strength pipe.

API 5L elongation figures vary with specimen dimensions. Values shown for 0.2 sq. in. specimen.

API X70 and X80 Pipe

X60,X65,X70 and X80 Line Pipe Physical Properties

API 5L Grade	Yield Strength min. (ksi)	Tensile Strength min. (ksi)	Yield to Tensile Ratio (max.)	Elongation min. %1
A	30	48	0.93	28
B	35	60	0.93	23
X60	60	75	0.93	19
X65	65	77	0.93	18
X70	70	82	0.93	17
X80	80	90	0.93	16

SEAMLESS API PIPELINE

Seamless X60,X65,X70 and X80 Line Pipe:

Specification	Grade	C Max	Mn Max	P Max	S Max	Other
Chemical Requirements, Percent (Product)
API 5L PSL 1a	A B X42 X45,X52,X56 X60e,X65e,X70e	0.22 0.28 0.28 0.28 0.28	0.90 1.20 1.30 1.40 1.40	0.030 0.030 0.030 0.030 0.030	0.030 0.030 0.030 0.030 0.030	-- b,d c,d c,d c,d
API 5L PSL 2a	B X42 X46,X52,X56 X60e,X56e X70e,X80e	0.24 0.24 0.24 0.24 0.24	1.20 1.30 1.40 1.40 1.40	0.025 0.025 0.025 0.025 0.025	0.015 0.015 0.015 0.015 0.015	b,c c,d c,d c,d c,d

ERW API LINE PIPE

ERW X60,X65,X70 and X80 Line Pipe:

Specification	Grade	C Max	Mn Max	P Max	S Max	Other
Chemical Requirements, Percent (Product)
API 5L PSL 1a	A B X42 X46,X52,X56 X60e X65e X70e	0.22 0.26 0.26 0.26 0.26 0.26 0.26	0.90 1.20 1.30 1.40 1.40 1.45 1.65	0.030 0.030 0.030 0.030 0.030 0.030 0.030	0.030 0.030 0.030 0.030 0.030 0.030 0.030	-- b,d c,d c,d c,d c,d c,d
API 5L PSL 2a	B X42 X46,X52,X56 X60e X65e X70e X80e	0.22 0.22 0.22 0.22 0.22 0.22 0.22	1.20 0.30 1.40 1.40 1.45 1.65 1.85	0.025 0.025 0.025 0.025 0.025 0.025 0.025	0.015 0.015 0.015 0.015 0.015 0.015 0.015	b,d c,d c,d c,d c,d c,d c,d

• Joint preparation and line-up must be carefully controlled. High- low conditions should be held to a minimum.

• Thin walled [up to 3/8” (10mm)] X-80 pipe can be welded with Shield-Arc® 90. Weld X-70 pipe with either Shield-Arc 80 or Shield-Arc 70+. Pipes X-60 and X-65 pipes can be welded with Fleetweld 5P+, Shield-Arc HYP, Shield-Arc HYP+,Shield-Arc 70+ or Shield-Arc 80.

• Preheat cold pipe to at least 70°F (21°C). The exact degree of pre- heat depends on the pipe steel, but preheating up to 350°F (177°C) would not be unreasonable for X-80 pipe.

• An internal fit-up clamp should not be removed until the entire root pass is complete.

• Fewer defects will be seen if restarts and stops (craters) are ground out, with the stops ground down to a feathered edge.

• Don’t start the root pass welds at exactly the top of the pipe (12 o’clock position) or end them at exactly the bottom (6 o’clock position). Stopping the weld at the 6 o’clock position can con- tribute to burnthrough, tie-in or suck-back problems.

• When finishing an electrode on the root pass, a fast pullout (flicking the electrode) can reduce the size of the remaining keyhole, mak- ing tie-in easier.

• Since reverse polarity (DC+) is commonly used by U.S. pipeline operators for root pass welding, switch to straight polarity (DC-) when burn through, internal undercut and hollow bead defects persist. Polarity change is an essential variable in API 1104 code - requiring a procedure qualification.

• Excessive travel speed in either the root or hot pass will cause defects.

• Start and complete the hot pass immediately after completion of the root pass.

• If the temperature of the pipe has dropped below the prescribed interpass temperature, reheat the entire joint.

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