Section 4 Wire-flux combinations for submerged-arc automatic welding

4.1 General

4.1.1 Wire-flux combinations for single and multiple electrode submerged-arc automatic welding, without the use of temporary backing, are divided into the following two categories:

For use with the multi-run technique.
For use with the two-run technique.

Where particular wire-flux combinations are intended for welding with both techniques, tests are to be carried out for each technique.

4.1.2 Dependent on the results of mechanical and other tests, approval will be allocated as one of the grades from Table 11.1.1 Welding consumable grades appropriate to structural and low temperature service steel grades.

4.1.3 The suffixes T or M will be added after the grade mark to indicate approval for the two-run technique or multi-run technique respectively.

4.1.4 Wire-flux combinations satisfying the requirements for multi-run or two-run techniques will also be approved for fillet welding in the downhand and horizontal-vertical position, subject to agreement by the manufacturer.

4.1.5 If the consumable combination is in compliance with the requirements of the hydrogen test given in Ch 11, 3.4 Hydrogen test, a suffix H15, H10, or H5 will be added to the grade. Table 11.4.1 Minimum low hydrogen approval requirements for wire-flux combinations shows the mandatory levels of low hydrogen approval for the various approval grades.

Table 11.4.1 Minimum low hydrogen approval requirements for wire-flux combinations

Approval grade	'H' grade for Multi-run	'H' grade for Two-run
1 (1N), 2 (2N), 3 (3N)	NR	NR
1Y, 2Y, 3Y, 4Y	NR	NR
2Y40 to 5Y40	H15	NR
3Y47	H10	H15

3Y42 to 5Y42	H10	H15
3Y46 to 5Y46	H10	H10
3Y50 to 5Y50	H10	H10
3Y55 to 5Y55	H5	H10
3Y62 to 5Y62	H5	H5
3Y69 to 5Y69	H5	H5
3Y89 to 4Y89	H5	H5
3Y96 to 4Y96	H5	H5
1Ni	H15	NR
2Ni	H15	NR
3Ni	H15	NR
5 Ni (see Note 2)	NR	NR
9 Ni (see Note 2)	NR	NR
Note 1. NR – Not required. Approval can be obtained when requested. Note 2. Assumes use of an austenitic, non-transformable, filler material.

4.1.6 For each strength level, wire-flux combinations which have satisfied the requirements for a higher toughness grade are considered as complying with the requirements for a lower grade.

4.1.7 Wire-flux combinations approved with multi-run technique for normal and higher strength levels up to and including 'Y' are also considered suitable for welding steels in the three strength levels below that for which they have been approved.

4.1.8 Wire-flux combinations approved with multi-run technique for strength levels Y40 to Y50, but excluding Y47 are also considered suitable for welding steels in two strength levels below that for which they have been approved.

4.1.9 Wire-flux combinations approved with multi-run technique for strength levels Y47, Y55 and above are also considered suitable for welding steels in only one strength level below that for which they have been approved.

4.1.10 Wire-flux combinations approved with multi-run technique for strength level Y89 are considered suitable for welding steels only in this strength level.

4.1.11 Wire-flux combinations approved with multi-run technique for strength level Y96 are also considered suitable for welding steels in one strength level below that for which they have been approved.

4.1.12 Wire-flux combinations with two-run technique approval are not considered suitable for welding steels of any other strength level with that technique, see Ch 11, 4.5 Approval tests for two-run technique 4.5.1.

4.1.13 The welding current may be either a.c. or d.c. (electrode positive or negative) according to the recommendation of the manufacturer. If both a.c. and d.c. are recommended, a.c. is to be used for the tests.

4.1.14 Wire-flux combinations for multiple electrode submerged-arc welding will be subject to separate approval tests. These are to be carried out generally in accordance with the requirements of this Section.

4.1.15 Wire-flux combinations are not naturally low hydrogen in character, but for the lower strength grades of steel low hydrogen testing is not normally a requirement for approval. With higher strength steels it is more important and Table 11.4.1 Minimum low hydrogen approval requirements for wire-flux combinations shows the mandatory minimum low hydrogen status required for approval of wire-flux combinations.

4.2 Approval tests for multi-run technique

4.2.1 Where approval for use with the multi-run technique is requested, deposited metal and butt weld tests are to be carried out.

4.3 Deposited metal test assemblies (multi-run technique)

4.3.1 One deposited metal test assembly is to be prepared as shown in Figure 11.4.1 Deposited metal test assembly, using any of the grades of steel in Table 11.1.1 Welding consumable grades appropriate to structural and low temperature service steel grades up to a strength level which is not more than two levels above that for which approval is sought.

Figure 11.4.1 Deposited metal test assembly

4.3.2 For Y47 grades, as an alternative to Figure 11.4.1 Deposited metal test assembly, the thickness of the plate used for the test assembly may be taken as 50 mm.

4.3.3 The bevelling of the plate edges is to be carried out by machining or mechanised gas cutting. In the latter case any remaining scale is to be removed from the bevelled edges.

4.3.4 Welding is to be in the downhand position, and the direction of deposition of each run is to alternate from each end of the plate. After completion of each run, the flux and welding slag are to be removed. Between each run, the assembly is to be left in still air until it has cooled to less than 250°C, the temperature being taken in the centre of the weld, on the surface of the seam. The thickness of the layer is to be not less than the diameter of the wire nor less than 4 mm, unless it is clearly stated as part of the consumable manufacturer's published recommendations.

4.3.5 The welding conditions (amperage, voltage and rate of travel) are to be in accordance with the recommendations of the manufacturer and are to conform with normal good welding practice for multi-run welding.

4.3.6 The chemical analysis of the deposited weld metal in each test assembly is to be supplied by the manufacturer and is to include the content of all significant alloying elements. The results of the analysis are not to exceed the limit values specified in the standards or by the manufacturer, the narrower tolerances being applicable in each case.

4.3.7 Two longitudinal tensile and three impact test specimens are to be taken from each test assembly as shown in Figure 11.4.1 Deposited metal test assembly. Care is to be taken that the axes of the tensile test specimens coincide with the centre of the weld and the mid-thickness of the plates. The impact test specimens are to be cut perpendicular to the weld with their axes 10 mm from the upper surface. The notch is to be positioned in the centre of the weld and cut in the face of the test specimen perpendicular to the surface of the plate.

4.3.8 In those cases where two-run technique approval is also sought, only one longitudinal tensile specimen need be prepared and tested from this assembly.

4.3.9 The results of all tests are to comply with the requirements of Table 11.4.2 Requirements for deposited metal tests (wire-flux combinations), as appropriate.

Table 11.4.2 Requirements for deposited metal tests (wire-flux combinations)

Grade	Yield stress N/mm² minimum	Tensile strength N/mm²	Elongation on 50 mm % minimum	Charpy V-notch impact tests
Grade	Yield stress N/mm² minimum	Tensile strength N/mm²	Elongation on 50 mm % minimum	Test temperature °C	Average energy (see Note) J minimum
1N, 2N, 3N	305	400 – 560	22	+20, 0, –20	34
1Y, 2Y, 3Y, 4Y	375	490 – 660	22	+20, 0, –20, –40	34
2Y40, 3Y40, 4Y40, 5Y40	400	510 – 690	22	0, –20, –40, –60	39
3Y47	460	570 – 720	19	–20	64
3Y40	400	510 – 690	22	–20	39
3Y42	420	520 – 680	20	–20	47
3Y46	460	540 – 720	20	–20	47
3Y50	500	590 – 770	18	–20	50
3Y55	550	640 – 820	18	–20	55
3Y62	620	700 – 890	18	–20	62
3Y69	690	770 – 940	17	–20	69
3Y89	890	940 – 1100	14	–20	69
3Y96	960	980 - 1150	13	–20	69
4Y40	400	510 – 690	22	–40	39
4Y42	420	520 – 680	20	–40	47
4Y46	460	540 – 720	20	–40	47
4Y50	500	590 – 770	18	–40	50
4Y55	550	640 – 830	18	–40	55
4Y62	620	700 – 890	18	–40	62
4Y69	690	770 – 940	17	–40	69
4Y89	890	940 – 1100	14	–40	69
		980 - 1150	13	–40	69
5Y40	400	510 – 690	22	–60	39
5Y42	420	520 – 680	20	–60	47
5Y46	460	540 – 720	20	–60	47
5Y50	500	590 – 770	18	–60	50
5Y55	550	640 – 820	18	–60	55
5Y62	620	700 – 890	18	–60	62
5Y69	690	770 – 940	17	–60	69
1¹/₂Ni	375	490-640	22	–80	34
2¹/₄Ni	375	490-640	22	-90	34
3¹/₂Ni	375	490 - 610	25	–100	34
5 Ni	400	540-740	25	–120	34
9 Ni	400	640-790	25	–196	34
Note Energy values from individual impact test specimens are to comply with Ch 11, 1.4 Approval procedures 1.4.3.

4.4 Butt weld test assemblies (multi-run technique)

4.4.1 One butt weld test assembly is to be prepared as shown in Figure 11.4.2 Butt weld test assembly (multi-run technique).

4.4.2 The grade of steel used for the preparation of the test assembly are to be as follows:

Grade 1 wire-flux combination	A
Grade 2 wire-flux combinations	A, B or D
Grade 3 wire-flux combinations	A, B, D or E
Grade 1Y wire-flux combination	AH32 or AH36
Grade 2Y wire-flux combinations	AH32, AH36, DH32 or DH36
Grade 3Y wire-flux combinations	AH32, AH36, DH32, DH36, EH32 or EH36
Grade 4Y wire-flux combinations	AH32, AH36, DH32, DH36, EH32, EH36, FH32 or FH36
Grade 2Y40 wire-flux combination	AH40 or DH40
Grade 3Y40 wire-flux combinations	AH40, DH40 or EH40
Grade 4Y40 wire-flux combinations	AH40, DH40, EH40 or FH40
Grade 5Y40 wire-flux combinations	AH40, DH40, EH40 or FH40
Grade 3Y47 wire-flux combinations	EH47

Where Grade 32 higher tensile steel is used, the tensile strength is to be not less than 490 N/mm². The chemical composition, including the content of grain refining elements, is to be reported in all cases where higher tensile steel is used.

Figure 11.4.2 Butt weld test assembly (multi-run technique)

4.4.3 For all other grades, the steel plates used are to be selected by reference to Table 11.1.1 Welding consumable grades appropriate to structural and low temperature service steel grades, and are to have at least their chemical composition and tensile properties within the limits specified for that grade in Ch 3 Rolled Steel Plates, Strip, Sections and Bars. The strength grade used is to be the same as that for which approval is sought, and the toughness grade is to be no higher than that for which approval is also sought.

4.4.4 The plate edges are to be prepared to form a single V-joint, the included angle between the fusion faces being 60° and the root face being 4 mm. The bevelling of the plate edges is to be carried out by machining or mechanised gas cutting. In the latter case, any remaining scale is to be removed from bevelled edges.

4.4.5 Welding is to be carried out in the downhand position by the multi-run technique, and the welding conditions are to be the same as those adopted for the deposited metal test assembly. The back sealing run is to be applied in the downhand position after cutting out the root run to clean metal.

4.4.6 It is recommended that the welded assembly be subjected to a radiographic examination to ascertain if there are any defects in the weld prior to the preparation of test specimens.

4.4.7 The test specimens as shown in Figure 11.3.3 Butt weld test assembly position of impact test specimens and Figure 11.4.2 Butt weld test assembly (multi-run technique) are to be prepared from each test assembly.

4.4.8 The results of all tensile and impact tests are to comply with the requirements of Table 11.4.3 Requirements for butt weld tests (wire-flux combinations), as appropriate. The position of fracture of the transverse tensile test is to be reported.

Table 11.4.3 Requirements for butt weld tests (wire-flux combinations)

Grade	Tensile strength N/mm²	Bend test ratio:	Charpy V-notch impact tests
Grade	Tensile strength N/mm²	Bend test ratio:	Test temperature °C	Average energy (see Notes 1 and 2) J minimum
1N, 2N, 3N	400	3	+20, 0, –20	34
1Y, 2Y, 3Y, 4Y	490	3	+20, 0, –20, –40	34
2Y40, 3Y40, 4Y40, 5Y40	510	3	0, –20, –40, –60	39
3Y47	570 – 720	4	–20	64
3Y40	510	3	–20	39
3Y42	520 – 680	4	–20	47 (41)
3Y46	540 – 720	4	–20	47
3Y50	590 – 770	4	–20	50
3Y55	640 – 820	5	–20	55
3Y62	700 – 890	5	–20	62
3Y69	770 – 940	5	–20	69
3Y89	940	6	–20	69
3Y96	980	7	–20	69
4Y40	510	3	–40	39
4Y42	520 – 680	4	–40	47 (41)
4Y46	540 – 720	4	–40	47
4Y50	590 – 770	4	–40	50
4Y55	640 – 820	5	–40	55
4Y62	700 – 890	5	–40	62
4Y69	770 – 940	5	–40	69
4Y89	940	6	–40	69
4Y96	980	7	–40	69
5Y40	510	3	–60	39
5Y42	520 – 680	4	–60	47 (41)
5Y46	540 – 720	4	–60	47
5Y50	590 – 770	4	–60	50
5Y55	640 – 820	5	–60	55
5Y62	700 – 890	5	–60	62
5Y69	770 – 940	5	–60	69
1¹/₂Ni	490	3	–80	27
2¹/₄Ni	490	3	-90	27
3¹/₂Ni	490	3	–100	27
5 Ni	540	4	–120	27
9 Ni	640	4	–196	27
Note 1. Energy values from individual impact test specimens are to comply with Ch 11, 1.4 Approval procedures 1.4.3. Note 2. Values in ( ) apply only to two-run technique impact test specimens.

4.4.9 The bend test specimens can be considered as complying with the requirements if, after bending, no cracks or other open defects exceeding 3 mm in dimension can be seen on the outer surface.

4.5 Approval tests for two-run technique

4.5.1 Where approval for use with the two-run technique is requested, two butt weld test assemblies are to be prepared and tested using plates of the strength level for which approval is required. Each strength level requires separate approval.

4.5.2 Two welded assemblies are to be made from a pair of plates of matching thicknesses. The thickness of the thicker pair of plates will be the maximum for which the approval is valid. The second assembly is to be welded from plates having approximately half of the thickness of the first assembly.

4.6 Butt weld test assemblies (two-run technique)

4.6.1 The grade of steel used for the preparation of the test assemblies is not to be of any higher grade (impact toughness) than that for which approval is required. The chemical composition, including the content of grain refining elements, and the strength properties of the plates used, are to be reported.

4.6.2 The maximum diameter of wire and the edge preparation to be used are to be in accordance with Table 11.4.4 Butt weld assembly preparation. Small deviations in the edge preparation may be allowed if requested by the manufacturer. The bevelling of the plate edges is to be performed by machining or mechanized gas cutting. In the latter case, any remaining scale is to be removed from the bevelled edges. The root gap should not exceed 0,7 mm.

Table 11.4.4 Butt weld assembly preparation

Plate thickness mm	Recommended edge preparation	Maximum diameter of wire mm
12,5		5
20–25		6
35–40		7

4.6.3 Each butt weld is to be welded in two runs, one from each side, using amperages, voltages and travel speeds in accordance with the recommendations of the manufacturer and normal good welding practice. After completion of the first run, the flux and welding slag are to be removed and the assembly is to be left in still air until it has cooled to less than 100°C, the temperature being taken in the centre of the weld, on the surface of the seam.

4.6.4 It is recommended that the butt weld assemblies be subjected to radiographic examination to ascertain if there are any defects in the weld prior to the preparation of test specimens.

4.6.5 The test specimens, as shown in Figure 11.4.3 Butt weld test assembly (two-run technique) and Figure 11.4.4 Butt weld test assembly (two-run technique): position of impact test specimens, are to be prepared from each test assembly, except as detailed in Ch 11, 4.6 Butt weld test assemblies (two-run technique) 4.6.8. The edges of two of the discards are to be polished and etched, and must show complete fusion and inter-run penetration of the welds. At each cut in the test assembly, the edges are also to be examined to ensure that complete fusion has taken place.

Figure 11.4.3 Butt weld test assembly (two-run technique)

Figure 11.4.4 Butt weld test assembly (two-run technique): position of impact test specimens

4.6.6 The results of transverse tensile and impact tests are to comply with the requirements of Table 11.4.3 Requirements for butt weld tests (wire-flux combinations) as appropriate. The position of fracture of the transverse tensile tests is to be reported.

4.6.7 The bend test specimens can be considered as complying with the requirements if, after bending, no crack or other open defects exceeding 3 mm in dimensions can be seen on the outer surface. One of the specimens from each assembly is to be tested with the side first welded in tension, and the second specimen with the other side in tension.

4.6.8 The longitudinal tensile specimen shown in Figure 11.4.3 Butt weld test assembly (two-run technique) is to be prepared from the thicker assembly, even in those cases where multi-run technique approval is also sought. This test specimen is to be machined to the dimensions shown in Ch 11, 2.1 Dimensions of test specimens 2.1.1 and the longitudinal axis is to coincide with the centre of the weld about 7 mm below the plate surface on the side from which the second run is made. The test specimen may be given a hydrogen release treatment in accordance with Ch 11, 2.1 Dimensions of test specimens 2.1.1. The results of this test are to comply with the requirements of Table 11.4.2 Requirements for deposited metal tests (wire-flux combinations).

4.6.9 The chemical analysis of the weld metal of the second run in each assembly is to be determined and reported. This is to include the content of all significant elements. The results of the analysis are not to exceed the limit values specified in the standards or by the manufacturer, the narrower tolerances being applicable in each case.

4.7 Annual tests

4.7.1 Annual tests are to consist of at least the following:

For wire-flux combinations approved for the multi-run technique, one deposited metal test assembly.
For wire-flux combinations approved for the two-run technique, one butt weld test assembly using plate material 20 to 25 mm in thickness. For Y47, the thickness of plate material may be taken as 50 mm.
A hydrogen test for Y89 and Y96 grades.

4.7.2 The deposited metal assemblies are to be prepared and tested in accordance with Ch 11, 4.3 Deposited metal test assemblies (multi-run technique), except that only one longitudinal tensile, three impact test specimens and a chemical analysis are required.

4.7.3 The butt weld test assemblies are to be prepared and tested in accordance with Ch 11, 4.6 Butt weld test assemblies (two-run technique), except that only one transverse tensile, two bend, three impact test specimens and a chemical analysis are required. One longitudinal tensile test specimen is also to be prepared where the wire-flux combination is approved solely for the two-run technique.

4.7.4 Where a wire-flux combination is approved for welding a range of steels with different specified minimum strength levels, steel of the highest strength approved is to be used for the preparation of the butt weld assembly required by Ch 11, 4.7 Annual tests 4.7.1.(b).