KOBELCO

WELDING
GLOBAL MANUFACTURING BASES
AND OFFICES
ASIA
JAPAN:
KOBE STEEL, LTD., Welding Business
Global Operations and Marketing Department

TODAY
Marketing Center
Tel. (81) 3 5739 6331 Fax. (81) 3 5739 6960

21
KOREA:
KOBE WELDING OF KOREA CO., LTD.
Tel. (82) 55 292 6886 Fax. (82) 55 292 7786

KOBELCO WELDING MARKETING OF KOREA CO., LTD.

Tel. (82) 51 329 8950 to 8952 Fax. (82) 51 329 8949

CHINA:
Vol..
KOBE WELDING OF SHANGHAI CO., LTD.
Tel. (86) 21 6191 7850 Fax. (86) 21 6191 7851

KOBE WELDING OF TANGSHAN CO., LTD.

2018 No.2
Tel. (86) 315 385 2806 Fax. (86) 315 385 2829
KOBELCO Puts the Customer First with All-in-One Product and Service
KOBE WELDING OF QINGDAO CO., LTD.
Tel. (86) 532 8098 5005 Fax. (86) 532 8098 5008

SINGAPORE:
KOBELCO WELDING ASIA PACIFIC PTE. LTD.
Tel. (65) 6268 2711 Fax. (65) 6264 1751

THAILAND:
THAI-KOBE WELDING CO., LTD.
Tel. (66) 2 636 8650 to 8652 Fax. (66) 2 636 8653
KOBE MIG WIRE (THAILAND) CO., LTD.
Tel. (66) 2 324 0588 to 0591 Fax. (66) 2 324 0797

VIETNAM:
REP. OFFICE of THAI-KOBE WELDING in DONG NAI
Tel. (84) 61 395 5218

MALAYSIA:
KOBE WELDING (MALAYSIA) SDN. BHD.
Tel. (60) 4 3905792 Fax. (60) 4 3905827

INDONESIA:
P.T. INTAN PERTIWI INDUSTRI
(Technically Collaborated Company)
Tel. (62) 21 639 2608 Fax. (62) 21 649 6081

INDIA:
KOBELCO WELDING INDIA PVT. LTD.
Tel. (91) 124 4010063 Fax. (91) 124 4010068

EUROPE
NETHERLANDS:
KOBELCO WELDING OF EUROPE B.V.
Tel. (31) 45 547 1111 Fax. (31) 45 547 1100
SWEDEN:
KOBELCO WELDING OF EUROPE AB
Tel. (46) 31 767 55 91

AMERICA
USA:
KOBELCO WELDING OF AMERICA INC.
Tel. (1) 281 240 5600 Fax. (1) 281 240 5625
 Preface ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■  Preface ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

KOBELCO Inaugural address Welding automation

WELDING by Akira Yamamoto, with ISHIMATSU,
TODAY No.2
2018 new Head of the Welding Business the portable robot, and PLM
C 21 NTENTS
Vol. Dear KWT readers! My name is Akira Dear KWT readers! My name is Hiroyuki Shimizu, newly appointed to the Head
page
Yamamoto, the new Head of the Welding of the Technical Center as Mr. Nagata’s successor in June, 2018 and I’d like to
2 Business. I succeeded Mr. Koshiishi, my
predecessor, in April 2018. I would like to express
express my warmest thanks for your continuous patronage of the KOBELCO
group’s products. Following Mr. Nagata’s last article in KWT20-2 (2017), I will discuss the direction of KOBELCO’s
my heartfelt gratitude for your kind patronage of technological development and focus on how welding automation is part of our effort in the Welding Business to
and continuous support for KOBELCO products. achieve the KOBE STEEL group’s mid-term management plan called “KOBELCO VISION G+.”
I wish to begin my inaugural address by Firstly, I am happy to introduce the new, small portable welding robot named ISHIMATSU (Figure 1) that was
Welding automation
deeply and sincerely apologizing for having added to our robotic product range last December. It has already been utilized in parallel with ARCMANTM robots, the
with ISHIMATSU, caused you substantial trouble and main Series of KOBELCO robots used by a number of steel fabricators in Japan. While an ARCMANTM robot takes
the portable robot, and PLM
inconvenience due to the misconduct related up space in a factory, the ISHIMATSU does not because it is both portable and fixed directly upon the work pieces it
page
to quality management committed by KOBE is welding. On the other hand, it requires some assistance from an operator, whereas the ARCMAN TM can finish
3 STEEL and the KOBE STEEL Group. As for the Akira Yamamoto
Welding Business, I would like to report that we Managing Executive Officer,
welding an entire workpiece without any help. Remarkably, ISHIMATSU has increasingly been used for welding on
Head of the Welding Business building construction sites. While there are pros and cons to both ISHIMATSU and ARCMANTM, we are happy to be
commissioned an independent body to KOBE STEEL, LTD. able to offer a choice that will match users’ situations. We believe that there are large potential markets for the
evaluate our voluntary inspections of quality at ISHIMATSU, particularly
domestic as well as overseas production sites and that nothing inappropriate in areas or on workpieces PLM(Product Life cycle Management)
B91 Series welding consumables related to quality has been observed. In addition, we promise that we will where a large robotic
for Grade 91 steels continue to carry out the highest standard of quality control. system like ARCMAN TM Planning Designing Production Sales Maintenance
page
We in the Welding Business have been conducting our activities in is not applicable but
8 accordance with our vision, to be the most reliable welding solutions automated welding is ERP

company in the world. Some of these activities were on display at the Japan desired. While we have 3D CAD Model
MES
Integration
International Welding Show held in Tokyo last April, including a proposed not yet started marketing it Production
operation PLC,
Production
information
means of manpower-saving automation that combines four robotic welding overseas, we are investi- Production Line

systems with the most suitable consumable, as well as our range of welding gating whether to start Sensor network,
Field network
PF-N5/US-609S for SAW on 9%Ni steels: consumables created specifically for the shipbuilding, energy and automobile recommending it for
Excellent solution in horizontal
and flat positions industries. (See the bulletin article on pages 9-10 in this issue for more details.) automation on large-scale Figure 1: ISHIMATSU welding robots Figure 2: Integration of product life cycle in PLM
page
During the show, we could highlight the achievements of our activities to many visitors
structures.
9 at the KOBELCO booth, while emphasizing our plans to develop welding automation
and manpower savings further by utilizing IoT and AI technologies in the future.
Secondly, I will discuss the function of robotic welding systems utilizing KOBELCO’s Information and
Communication Technology (ICT). We have already improved productivity by using ICT as discussed in last
year’s KWT. “Vertical integration of production” is a key concept of our activity, as shown in Figure 2. Product life
On the other hand, the welding solution many of our customers rely on is not
cycle management (PLM) is a holistic management system, based on ICT, of product-related information covering
related to robotic automation at all; for example, shielded metal arc welding with
covered electrodes remains one of the most convenient of welding processes.
the whole lifecycle of products, such as design, production, maintenance, disposal and recycling, with the aim of
KOBELCO-Your Best Partner maximizing profits. Although it is not easy to create operation commands that order a robot to conduct steady
is highlighted at JIWS 2018 The environment surrounding the welding business is changing day by day, and welding with three-dimensional CAD data, ICT has allowed us to achieve it. Furthermore, it will allow us to
so are most customers. By staying sensitive to the changes, we will be able not achieve better traceability and perform organic control by recording the conditions at times of spatter and fume
only to develop new products that match their needs but to enhance the generation and stops, in addition to recording overall welding conditions and system operations.
distinctiveness and added-value of our products.
The above-mentioned robots and PLM were exhibited
As our KOBELCO members continue to visit your countries and regions, please let at the Japan International Welding Show (JIWS) held in
them know your problem(s), trouble(s) and/or needs for your welding operations. Tokyo last April. KOBELCO representatives will visit
Lastly, our vision, aiming to be the most reliable welding solutions company in the your countries and regions directly to introduce our
world that was established and succeeded by my predecessors, Messrs. Kasuya and latest products and technologies including the above
Koshiishi, will never be changed even as I become the Head of the Welding Business. I and listen to your requests. As your requests are always
surely believe that our responsibilities are to provide you with stable, high quality changing, I believe it is important for us to deal with
KOBELCO WELDING TODAY
products and excellent services, cultivated by the high capability of Monodzukuri your needs properly. By rotating the circle of “needs→
is published by
Marketing Center (production system innovation), so as to obtain your full trust in the KOBELCO brands. Hiroyuki Shimizu dealing→improvement” and receiving feedback on
Head of the Technical Center progress, we will continue deepening our activities to
Welding Business,
As we promise to make wholehearted efforts in order to meet your Welding Business
KOBE STEEL, LTD. KOBE STEEL, LTD. achieve our business vision of “being the most reliable
expectations, your support is most appreciated.
URL: http//www.kobelco.co.jp/english welding solutions company in the world.”
1 2
Technical Highlight ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ KOBELCO
WELDING
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B91 Series welding consumables Table 2: Trend of AWS B9/B91 standard
Vol.21 No.2 2018

for Grade 91 steels Upper limit of Upper limit of PWHT   Chemical compositions and Ac1  
Year
Mn+Ni content temperature at
in deposited metal specified for testing
Reference
(Year of revision) *2
3 transformation point of B91 Series
 
(mass %) *1 (°
C)   welding consumables
Up to 759 (SMAW) or B9: SMAW, GMAW, Although 9Cb Series welding consumables are not
Not regulated*3 GTAW (1996)
2004 760 SAW (1997) entirely compatible with AWS specifications because
they are designed to obtain comparatively high Mn+Ni
B9: GMAW, GTAW
(2005) content, they have been utilized successfully in domestic
2005
-2010
1.5 or 1.50 775 SMAW (2006) and overseas projects in which PWHT temperature
SAW (2007)
FCAW (2010) requirements have been relatively low. However, in
B9 deleted → B91
cases where following AWS specifications is mandatory,
From newly established particularly in overseas projects, these consumables
2010 1.40 775 B91: SAW (2011),
onwards FCAW (2012)
could not be applied.
SMAW (2014) *4
KSL originally developed and marketed the B9 Series
Note: *1) Wire or cut rod chemistry in case of GMAW and GTAW
 *2) AWS Specification No.: SMAW: A5.5; SAW: A5.23; GMAW & GTAW: consumables to be compatible with AWS specifications.
they have been well-received by many domestic and    A5.28; FCAW: A5.36 The B91 Series consumables were later developed to
1 Preface
  overseas boiler fabricators.
 *3) Sum of both Mn and Ni specified upper limit figures is 2.25
 *4) Revision of GMAW and GTAW is under discussion as of May, 2018. comply with stricter AWS requirements in 2012,
especially the ever-stricter limitations on Mn+Ni content.
The biggest concern in the field of thermal power On the other hand, an issue concerning high Cr ferritic Both tables show that the upper limits for Mn+Ni content
generation is the reduction of CO2 emissions. However, steel is the combined amount of Mn+Ni, which has have been repeatedly reduced in both sets of standards. In Table 3 shows the typical chemical compositions of
the most effective way of achieving that is to improve gradually come to be a subject of regulation. For example, welding Gr. 91 steels, this has allowed the upper limits on deposited metals and Ac1 transformation points, and Table
the efficiency of power generation, which requires such international standards bodies as ASME and AWS the temperature for PWHT, which is essential for reducing 4, the typical mechanical properties after PWHT, of the
steam at high temperature and pressure to be fed into have started to review the issue accordingly. residual stress after welding, to be eased higher. Following 9Cb and B91 Series consumables, respectively. It can be
power generating turbines. In Figure 1, it can be seen optimum PWHT, Gr. 91 weld metal exhibits a tempered seen that the B91 Series consumables are designed to
The B91 Series consumables, developed in accordance
that steam conditions (temperature and pressure) at martensite structure that provides excellent high provide the designated mechanical properties after PWHT
with these concerns, will be discussed as products
thermal power generation plants in Japan have trended temperature strength and toughness. However, it is while Mn+Ni content is controlled to be equal to or less
corresponding to the AWS standards.
up over the decades. well-understood that once the PWHT temperature exceeds than 1.0%, lower than that of the 9Cb Series consumables.
the Ac1 transformation point, fresh martensite transforms Figure 2 shows the relationship between Mn+Ni content
650
2 International standards
  back into austenite, and, during cooling, returns to become and actually measured Ac1 transformation points. It can be
fresh martensite again, leading to deterioration of creep and seen that typical Ac1 transformation points actually
steam temperature at turbine inlet (℃)

50 620
610
toughness properties. Therefore, the content of Mn and Ni measured with the B91 Series consumables show 800 °C
steam pressure at turbine inlet (MPa)

593 600 In recent years, international standards bodies have

40 moved to continuously modify requirements for both the needs to be kept low because these elements lower the Ac1 or over. Therefore, it is certain that higher PWHT
566 steam temperature
Mn+Ni content and the post weld heat treatment (PWHT) transformation point. (See Figure 2) temperatures can be applied.
31 550
30 temperature.
Table 3: Typical chemical composition of weld metal and Ac1
24.1
Tables 1 and 2 show the trends of ASME B31.1 and
steam pressure 500 Chemical composition of weld metal (mass%) Ac1
20
16.6 AWS B9/B91 standards respectively. Process Polarity   Consumables (°C)
C Si Mn Ni Cr Mo Nb V Co N Mn+Ni
450 Table 1: Trend of ASME B31.1 standard SMAW DCEP CM-9Cb 0.05 0.26 1.38 0.97 9.21 1.10 0.02 0.21 - 0.04 2.35 733
10 450
Upper limit of PWHT SAW AC PF-200S/US-9Cb 0.07 0.13 1.55 0.67 8.54 0.89 0.04 0.22 - 0.03 2.22 750
4.1 Mn+Ni temperature at actual procedure (°C) Reference 0.07 0.18
Year content GTAW DCEN TG-S9Cb (100%Ar) 1.01 0.69 8.63 0.91 0.04 0.18 - 0.02 1.70 765
Recommend- Mandatory (Year of revision)
0 400 (mass %) 0.08 0.27 0.38
ed condition condition GMAW DCEP MG-S9Cb (Ar-20%CO2) 1.29 8.86 0.98 0.03 0.19 - 0.02 1.67 -
1940    1960    1980    2000    2020
operation year 2008 Table 132 P-No. 5B SMAW DCEP CM-95B91 0.09 0.23 0.71 0.10 8.40 0.99 0.06 0.21 0.42 0.03 0.81 809
Not Base metal Ac1:
and 760 Group No. 1→
before
regulated about 800
Group No. 2 SAW AC PF-200S/US-90B91 0.09 0.29 0.74 0.16 8.64 1.03 0.04 0.20 0.40 0.04 0.90 808
Figure 1: Steam pressure and temperature Filler metal GTAW DCEN TG-S90B91 (100%Ar) 0.09 0.27 0.73 0.11 8.61 1.02 0.06 0.19 0.40 0.03 0.84 820
for thermal power generation in Japan unknown 775
GMAW DCEP MG-S90B91 (Ar-5%CO2) 0.12 0.24 0.64 0.15 8.47 0.98 0.05 0.18 0.41 0.04 0.79 813
2009 1.0≤Filler Base metal Ac1: Table 132 P-No. 15E
790
Thermal power generation plants, therefore, require -2013 metal <1.5 about 800 Group No. 1 (2009)
Table 4: Typical mechanical properties after PWHT of 9Cb Series and B91 Series consumables
special steels that can be utilized for long periods under Filler
metal<1.0 800
PWHT 0.2%OS TS vE+20° C TS
such high temperature and pressure steam conditions, such Process Polarity Trade Name Process Polarity Trade Name PWHT 0.2%OS vE+20° C
Base metal Ac1: condition (MPa) (MPa) (J) condition (MPa) (MPa) (J)
Filler
as high chromium (Cr) ferritic heat resisting steels 2014 metal<1.2
775 about 800 and
filler metal
Table 132 P-No. 15E
Group No. 1 (2014) SMAW DCEP CM-9Cb 750°
Cx5h 593 756 129 SMAW DCEP CM-95B91 760°
Cx2h 593 730 70
containing 9-12% Cr. Grade 91 (Gr. 91) steel is the main and A1 or A c1*2
PF-200S PF-200S
after SAW AC 740°
Cx8h 584 709 95 SAW AC 760°
Cx4h 578 719 62
high Cr ferritic steel that has been put into practical service <1.0 *1 125.1.3 (2014) For /US-9Cb /US-90B91
repair of casting TG-S9Cb TG-S90B91
in thermal power plant boilers worldwide. KOBE STEEL, GTAW DCEN (100%Ar) 740°
Cx8h 701 777 > 260 GTAW DCEN (100%Ar) 763°
Cx4h 579 713 216
LTD. (KSL) has developed and marketed both 9Cb Series Note: * 1 B9: SMAW, SAW, GTAW and FCAW
  *2 A1 or Ac1 in filler metals is determined either by analysis and MG-S9Cb MG-S90B91
GMAW DCEP 740°
Cx8h 568 698 120 GMAW DCEP 760°
Cx8h 529 689 74
and B9 Series consumables for welding Gr. 91 steels, and     calculation or by actual measurement (Ar-20%CO2) (Ar-5%CO2)

3 4
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WELDING
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840 250 Vol.21 No.2 2018

740℃x10h
 
5 Usability of the B91 Series

740℃x2h

760℃x2h

780℃x2h

760℃x8h

780℃x8h
820
200 consumables
800
The usability of B91 Series consumables has also been
780 150
improved. As for covered electrodes for SMAW, alloy

vE+20℃ (J)
Ac1 (℃)

760
core rods are generally used to stabilize the alloying
100 element quality in welds of high-Cr ferritic steels;
740 Co：0.40％
User spec.
however, electrode burn frequently happens during
Co：0.80％
50
≧27J
CM-95B91 welding especially with DC (Direct Current).
Co：0.40-0.42％(B91Series)
720 TG-S90B91 CM-95B91 is designed to reduce electrode burn and can
Co：Not contained
PF-200S/US-90B91 achieve welding even in a higher range of welding
700
0.5    1    1.5     2     2.5
0
20.0   20.5   21.0   21.5   22.0   22.5
current than the conventional TRUSTARCTM CM-9Cb.
PWHT Parameter (x103) A problem peculiar to SAW consumables on high-Cr
Mn+Ni Content of Weld metal (mass%) ferritic steels, namely, the burnt-slag that sticks on weld
(L.M.P.: (T+273)×(C+logt), T:℃, t:h, C=20)
bead surface, has also been reduced. Figure 7 shows a
Figure 2: Relationship between Mn+Ni content and Ac1 Figure 3: Microstructure of CM-95B91 Figure 5: Relationship between L.M.P. and vE+20C° comparison of bead appearances by SAW with the
combination of B91 wire and the newly improved flux,
Another feature of B91 Series consumables is the Figure 5 shows the relationship between L.M.P. and and the conventional flux, respectively. It can be seen
 
4 Mechanical properties of that the adhesive slag on bead surface is greatly reduced
addition of cobalt (Co). As Figure 2 suggests, the Ac1 notch toughness at +20°C.
transformation point tends to fall in relation to the increase
  B91 Series consumables with the improved SAW flux.
While notch toughness differs depending on the
in Mn+Ni content. While the B91 Series consumables Figure 4 shows the relationship between tensile welding consumables, all consumables exhibit better
contain Co, the element is not likely to affect the Ac1 strength (TS), 0.2% offset yield strength (0.2%OS) or Improved SAW flux
notch toughness when the L.M.P. is larger. In cases where
transformation point; after all, the consumables without 0.2% proof stress (0.2%PS) and the heat treatment the L.M.P. exceeds 21.0 x 10 3 , the obtained notch
Co also show a Ac1 transformation point that decreases in parameter, referred to as the Larson-Miller Parameter toughness values are sufficient enough for practical use.
relation to increases in Mn+Ni content. In fact, Co is (L.M.P.), in relation to CM-95B91, TRUSTARC TM
added for a different reason – restraining delta (δ) ferrite TG-S90B91 (AWS A5.28 ER90S-B9) and Figure 6 shows the creep rupture properties of
formation. Besides the Ac1 transformation point, another TRUSTARC T M PF-200S/US-90B91 (AWS A5.23 CM-95B91 and TG-S90B91.
influential factor on the Gr. 91 steels is the formation of δ F9PZ-EB91-B91).
ferrite structure. Because it is desirable that a weld 1000
contains no δ ferrite structure but 100% martensite It is clear that these welding consumables fully
structure, the Electric Power Research Institute (EPRI) satisfy the mechanical property requirements of Gr. 91 CM-95B91
TG-S90B91
proposed an index called Cr-Ni balance (CNB) less than steels (0.2%PS equal to or more than 415MPa and TS
10% in its report No. 1023199 “Guidelines and equal to or more than 585MPa) even at L.M.P.=22.0 x P91 steel (NIMS DATA SHEET NO.43A)

Applied stress (MPa)

Not ruptured yet: test in progress
Specifications for High-Reliability Fossil Power Plants.” 103 equivalent to PWHT parameter of 780°C x 8 hours Conventional SAW flux
The CNB equation is as follows: (i.e. high temperature and extended time).
100

CNB = (Cr equivalent) – (Ni equivalent)

740℃x10h
740℃x2h

760℃x2h

740℃x6h

760℃x8h

780℃x8h

1000 PWHT Temp.:740 780℃

= (Cr+6Si+4Mo+1.5W+11V+5Cb+9Ti+12Al) – Creep Temp.:590 670℃
(40C+30N+4Ni+2Mn+1Cu)
< 10 % (mass %) 900 P91 steel welded joint (P91 steel ×75％)
（MPa）

CM-95B91
Although Mn and Ni are known as the austenite 800 10
27.0   28.0   29.0   30.0   31.0    32.0
forming elements and the CNB equation also shows they TG-S90B91
Creep Parameter (x103)
0.2％PS, TS

can prevent δ ferrite formation, excessive amounts of Mn 700 PF-200S/ (L.M.P. : (T+273)×(C+logt), T: ℃, t:h, C=30)
and Ni are not allowed from the view point of AWS US-90B91
Open:0.2%PS
specification as well as Ac1 transformation point. For this 600 TS≧585MPa Figure 6: Creep rupture test results of CM-95B91 and TG-S90B91
Figure 7: Bead appearance comparison by SAW between
Solid:TS improved fluxes and conventional fluxes with B91 wire
reason, Co, another austenite forming element, is added
in order to restrain δ ferrite formation without changing 500
It confirms that these consumables provide more
Ac1 transformation point. sufficient creep rupture properties than those of the butt
0.2%PS≧415MPa joint welds (dotted line) even at PWHT temperature as
Figure 3 shows the microstructure of TRUSTARCTM 400
high as 780°C. Testing of the creep rupture properties of
20.0    20.5    21.0   21.5    22.0   22.5
CM-95B91 (AWS A5.5 E9015-B91), one of the B91 these consumables under an extended time creep condition
PWHT Parameter (x103)
Series consumables. The full tempered martensite (L.M.P.: (T+273)×(C+logt), T:℃, t:h, C=20) of 600°C x 100MPa is being carried out. For example, the
structure is easily recognized. tests of CM-95B91 and TG-S90B91 have passed 26,000
Figure 4: Relationship between L.M.P. and 0.2%P.S., T.S. and 21,000 hours respectively and are still in progress.

5 6
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PF-N5/US-609S for SAW on 9%Ni steels: Vol.21 No.2 2018

6 Notes on usage
  Excellent solution in horizontal
As B91 Series consumables provide high Cr-ferritic [References]
and flat positions
weld metals with a high degree of self-hardening, in (1) Heat-Resistant High-Cr Ferritic Steel Filler Metals for
comparison with those for 1.25Cr-0.5Mo and   Thermal Electric Power Boiler: KOBELCO WELDING TODAY
PREMIARC TM US-609S wire with PREMIARC TM The welded bead appearances of the first side and
2.25Cr-1Mo steels, their weld metals also have high   Vol. 12 No. 1 (2009)
PF-N5 bonded type flux provides an excellent cross-sectional macrostructures of both the 12 and 30
delayed-crack susceptibility. It is, therefore, essential to (2) ASME B31.1: POST WELD HEAT TREATMENT, 132.1 (2014)
solution for submerged arc welding (SAW) of 9% mm plates are shown in Figures 1 and 2, respectively.
strictly control welding procedures. If the pre-heating (3) ASME Sec. II Part C, SFA-5.5 (2015)
Ni steels in horizontal and flat positions. The
and interpass temperatures are properly controlled, (4) ASME Sec. II Part C, SFA-5.23 (2015) US-609S wire is made of Hastelloy*1 C276 and is
delayed cracks are prevented and sound weld metals (5) ASME Sec. II Part C, SFA-5.28 (2015) classified in AWS A5.14/A5.14M as ERNiCrMo-4. Its
can be obtained. Pre-heating as well as interpass 12 mm thick
(6) ASME Sec. II Part C, SFA-5.36 (2015) typical chemical composition is shown in Table 1.
temperatures of 250-350°C are generally recommended.
(7) EPRI 1023199: Guidelines and Specifications for The mechanical properties of all weld metal by
Impurities like P and S in the B91 Series consumables High-Reliability Fossil Power Plants (2011) PF-N5/US-609S are shown in Table 2.
should be kept as low as possible in order to prevent hot (Note:*1 Hastelloy is a trademark of Haynes International.)
cracks from occurring during welding.
Table 1: Typical chemical composition of US-609S (wire mass%)
Because the weld metals by the B91 Series C Si Mn P S Cu Ni
30 mm thick
consumables are more susceptible to hot crack and have US-609S wire 0.01 0.03 0.5 <0.001 0.003 <0.01 58.3
a higher solid-liquid coexistent region than those of AWS
A5.14/A5.14M ≤0.02 ≤0.08 ≤1.0 ≤0.04 ≤0.03 ≤0.50 Rem
1.25Cr-0.5Mo and 2.25Cr-1Mo steel weld metals, ERNiCrMo-4 Figure 1: Bead appearances of the first side
welding should not be performed with excessively high Cr Mo Fe W Co V Other
welding current and speed from the view point of US-609S wire 15.9 15.9 5.6 3.5 <0.01 <0.005 <0.1
welding procedure. As for PWHT condition, it should be AWS
A5.14/A5.14M
14.5
to
15.0
to
4.0 3.0
to ≤2.5 ≤0.35 ≤0.50
to
carefully selected, taking required tensile strength and ERNiCrMo-4 16.5 17.0 7.0 4.5
notch toughness properties into consideration, even Table 2: Typical mechanical properties of all weld metal
though B91 Series consumables can be utilized at a high Tensile test Charpy impact test
temperature such as 760-780°C. 0.2% PS TS EL vE-196°C 12 mm 30 mm
(MPa) (MPa) (%) (J)
thick thick
PF-N5/US-609S 459 729 46 88, 102, 99: Ave 96
7 Postscript
  Butt joint welding was performed on plates with
Figure 2: Cross-sectional macrostructures

thicknesses of 12 and 30 mm according to the The results of radiographic tests, butt joint tensile
There are three characteristics of the B91 Series welding parameters in Table 3. tests and Charpy impact tests as low as -196° C
welding consumables. The first is that they correspond (shown in Tables 4, 5, and 6 respectively) indicate that
Table 3: Welding parameters
to international standards such as ASME and AWS. the combination of PF-N5/US-609S can be applied for
Plate Welding condition
The second is that high PWHT temperatures can be thickness Pass sequence Pass Current Voltage Speed Speed
welding 9%Ni steels with satisfactory performances.
applied due to their high Ac1 transformation point. And mm (in.) (A) (V) (cm/min.) (in./min.)
Table 4: Radiographic test results
third, they are designed to obtain excellent creep 1 300 30 12
Plate thickness Indication size <0.8mm Indication size ≥0.8mm
rupture properties even in high PWHT conditions. 35° 2 340 40 16
(mm) in 600mm length in 600mm length
Table 5 compares the features of the B91 and 9Cb 12
3 4 3 360 40 16
12 0 6
1 4 360 26 50 20
Series consumables. （15/32） 6
2 30 20 8
60°7 5
5 360 40 16

Table 5: Feature of B91 and 9Cb Series consumables R5

35°
6 360 50 20 Table 5: Tensile test results of butt joint welds
2nd side 1st side 7 300 40 16 Plate thickness
B91 Series 9Cb Series Tensile stress (MPa) Fractured position
1 300 30 12 (mm)
AWS Specification ◎ (Mn+Ni≤ 1.0%) G grade (Mn+Ni>1.5%) 2 340 35 14 12 736, 736 Weld metal
Recommended 3 320 30 12 30 780, 783 Weld metal
PWHT temperature 760-780°
C 740-760°
C 40°
8 2 10 4∼5 340 45 18 Test method: ASME Sec. IX QW-150
45°
Ac1 temperature Approx. 800°
C Approx. 740°
C 30 6 300 40 16 Table 6: Charpy impact test results of butt joint welds
1
（19/16） 2 7∼9 340 26 50 20 Charpy impact test
Creep properties ◎ ○ 4
7 Plate thickness
15
15°
10 340 55 22 (mm) vE-196°
C (J) Lateral expansion (mm)
Note: ◎: excellent ○: good 16 11 320 30 12
12 99, 110, 106: Ave 105 1.11, 1.03, 1.14: Ave 1.09
60°
12 300 40 16
In the future, we will continue contributing to
11
13
R5 30 106, 102, 100 Ave 103 1.31, 1.13, 1.24: Ave 1.23
13∼15 360 35 14
customers’ expectations for diverse product ranges For detailed notes on usage such as recommended
2nd side 1st side 16 340 40 16
while maintaining high reliability as well as the Note : Base metal used: ASTM A553 Type-1. re-drying flux to prevent defects caused by moisture
capabilities for state-of-the-art development of welding Welding position: horizontal
and first pass welding parameters to avoid hot
Interpass temperature: 150° C; No preheating
consumables. Polarity: DCEP, Wire extension: 25mm, Torch angle: 22°
cracks, please refer to the catalog.
7 8
Bulletin ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■  KOBELCO
WELDING
TODAY
“KOBELCO-Your Best Partner” Vol.21 No.2 2018

is highlighted at JIWS 2018

T he 25th Japan International Welding Show (JIWS)

2018, Japan’s largest exhibition specializing in
welding and joining technology was held at Tokyo Big
Sight from April 25 to 28, 2018.
Under the exhibition’s main theme: “Think Future, Act
Now! Gateway to Great Success in Asia,” a record 240
companies and groups exhibited, while the total number of
participants over four days reached 100,428. According to Overview of the KOBELCO booth Live demonstration of the robotic welding systems (for steel fabrication) At the panel corner of the KOBELCO booth
the organizer, it was the largest number of participants since
the Lehman financial crisis.
attracted the interest of all visitors. The new F Series solid wires were also on display. A campaign products. Winners received a reprinted box of the
KOBE STEEL, LTD. displayed welding systems, recent trend in high speed welding of thin steel plates, such old FAMILIARC T M B-17 containing not welding
And for the steel fabrication industry, the demonstrations
consumables and procedures by means of live as used by car manufacturers, has been to apply a method electrodes, but Pocky® – a chocolate snack confectionary in
highlighted the “beam welding system,” which is
demonstrations and panels in order to support our that carefully controls the wire feeding, which greatly the shape of thin sticks. Many participants had fond
comprised of a special positioner, a boxing welding
customers’ “Monodzukuri” (production system minimizes spatter generation but can result in more rapid memories of the package and eagerly took it home as a gift
function and FAMILIARC TM MX-Z200MP (FCW).
innovation), under the catchphrase of “KOBELCO - Your wear of contact tips. The F Series solid wires were to their family.
Visitors from Japan and overseas seemed impressed at how
Best Partner ~Welding solutions for generations beyond.” designed to minimize spatter and restrain unstable wire
the welding lines, including the insides of scallops, were At the SWS corner, information on joining technology
In this report, I will provide some pictures and describe the feeding caused by wear of contact tips. One of the F Series
welded with excellent bead shape and low spatter. research, material testing, and analysis of chemical
KOBELCO displays. solid wires was seen to have been applied at another
components were displayed. Visitors could see actual
Another live demonstration for the steel fabrication company’s robotic welding demonstration.
Located near the entrance of East Hall 3, the KOBELCO analysis of ferrite content in duplex stainless steels being
industry featured ISHIMATSU, the small-sized portable
booth, decorated in black and KOBELCO blue, featured live The future of welding, in which the Internet of Things carried out with a digital microscope, which offers clear
type welding robot that was newly added to KOBELCO’s
demonstrations of robotic welding systems for shipbuilding, (IoT) has the potential to further improve productivity and magnification and image analysis from multiple fields.
product range in December, 2017, in combination with the
construction machinery and steel fabrication. Crowds of quality of robotic welding in the construction machinery Visitors appeared interested in the high-speed analysis
REGARCTM Process, the innovative low spatter welding
visitors gathered to watch and listen to the presenters from was also on display. For example, one proposed process derived from automatic consecutive photographing.
process. It showed low spatter welding of a
early morning of the first day to the end of the final day, would improve the ability to visualize welding procedures,
column-to-beam connection part. Surprised at the big We can proudly say that the exhibition allowed many
probably because welding automation is an urgent topic due by combining AP-SUPPORTTM (software to support
difference of arc sound and spatter generation between the visitors to understand that “KOBELCO is your best
to growing shortage of skilled welding operators. production) with a production monitoring camera. Another
REGARCTM Process and the conventional welding with partner” due to our welding solutions resulting from
showed how advanced automation and no-man operation
For the shipbuilding industry, visitors could see a live constant voltage characteristics, many visitors watched test combinations of welding consumables and robots,
could be achieved by applying the automatic off-line
demonstration of the robotic welding system for hull pieces being welded and then asked a barrage of questions investigation and inspection as well as technical services
teaching system that creates teaching data automatically
assembly that was launched into the market last year. It is to the presenters from KOBELCO ROBOTiX CO., LTD. that characterize the KOBELCO group.
after detecting the abnormalities during welding with AI.
comprised of ARCMANTM A30S, a small-sized robot (formerly KOBELCO ROBOTICS SERVICE CO., LTD.).
In summary, we would like to express our sincere
designed for automatic robotic welding of hull assembly, an The welding experience corner was set up so that anybody
On display at the panel corner were the welding appreciation to all who visited us at the KOBELCO booth.
auto-teaching system utilizing 3D-CAD data for designing could experience welding with the aforementioned new
consumables and processes that respond to such needs as
and FAMILIARCTM DW-100R, a flux cored wire (FCW) products for the steel fabrication industry. Under the
automation, high efficiency and declining welding skills in
exclusively developed for the system to provide excellent guidance of the Customer Service Promotion Department,
industries such as steel fabrication, automobile,
gap resistance and high speed vertical upward welding. SHINKO WELDING SERVICE CO., LTD. (SWS), a wide
shipbuilding, energy and construction machinery. For
range of visitors could experience and enjoy hands-on
For the construction machinery industry, the live examples, new consumables - FAMILIARCTM LB-50FT, a
welding, including potential customers, high school students
demonstrations featured the Ultra High Current GMAW low hydrogen type electrode featuring a soft arc and
participating in a welding competition held at the exhibition
Process, which pairs the new, large-sized ARCMANTM FAMILIARCTM MX-Z50F, an FCW exclusively used for
site, their friends, members of some Southeast Asian
A80 with FAMILIARCTM MX-A100D to deliver high steel plates with mill scale - were introduced for the steel
welding institutes, our agents’ sales representatives and Reprinted packages of older
efficiency, deep penetration and low spatter welding. It can fabrication industry, which has become more active due to products containing Pocky®,
even KOBELCO employees who rarely experience actual
produce welded butt joints with fluctuated root gaps by the Tokyo Olympics in 2020. The 1Z Series FCWs and a snack confectionary and
welding despite their affiliation with a well-known welding
using a newly-installed LASER gap-sensing function to solid wires for galvanized steel sheets also drew Al-foiled vacuum pack (in
products manufacturer. front)
sense the width of gaps instantaneously and continuously. considerable attention (despite their being aimed at a niche
Because the welding parameters are automatically adjusted market) presumably because of the interest in reducing the At the Shin-Yo-Kai (KOBELCO’s welding distribution Reported by
to control the optimum amount of deposited metals, the generation of porosity and spatter in the welding of network in Japan) corner, a contest was held in which Kazuyuki Harada,
system can provide beautiful bead appearances, which Zn-coated steel sheets. participants were quizzed on their knowledge of important Manager, Marketing Planning Section, Marketing Center

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