African Fusion June 2015

Böhler: pipe welding

Trends, processes and consumables for pipeline construction On May 19, 2015 at the SAIW’s City West premises in Johannesburg, Böhler UddeholmAfrica, in partnershipwith Fronius andGridweld, hosted a seminar and practical workshop on pipeline welding. African Fusion attends and summarises the keynote presentation by Voestalpine Böhler Welding’s Manfred Höfer (left), the company’s global pipeline segment manager.

B öhler has been pres- ent in South Africa for over 35 years, its global welding creden- tials go back 90 years

of 12 production plants. In addition, we support over 1 000 selected distribu- tion partners in 65 countries and have customers in 120 countries,” he says, adding that the company has been a Voestalpine Group company since 2007. On the pipeline side, its first bare welding rods were produced in 1926. “These were used in a very primitive joining process associated with large amounts of spatter and porosity,” he relates. “In order to improve the pro- cess at that time, however, a prototype flux-cored wire was produced, called Seelendraht. This development was not taken to market for a further 30 years, however,” he says. Böhler produced its first cellulosic electrode in the 1950s; its first solid gas metal arc welding (GMAW) wire in the 1960s; and began to manufacture flux-cored wire and its BVD range of low hydrogen vertical down pipeline electrodes in the 1970s. “Low hydrogen technology is now over 40 years old and it remains a sensitive topic for pipeline welding,” Höfer relates. Global pipeline welding trends Key to the ongoing improvements in pipeline construction is the introduction of new welding equipment and pipe

materials, which offer better productiv- ity, quality and reduced construction costs. Summarising the key trends, Höfer says that mechanised welding, and in particular, narrow gap welding with solid GMAW wire, offers signifi- cantly better productivity. “The use of solid, gas-shielded and self-shielded flux-cored wires and metal-cored wires continue to grow, while the use of cel- lulosic electrodes is expected to reduce in developed markets in favour of pro- cesses that offer higher productivity,” he predicts. The higher yield and tensile strengths associated with new pipe materials such X70 and X80 enable re- duced wall thickness and/or increased pipeline pressures, compared to the X60 and X65 grades. “Also, in the offshore industry, we are seeing increased de- mand for corrosion resistant alloy (CRA) pipe materials of types 625 and 825, for example, to combat the aggressive cor- rosive environment offshore. Displaying a bar chart showing the deposition rate comparisons for differ- ent pipeweldingoptions, Höfer says that if a productivity index of one is allocated to downhand pipe welding using cellu- lose (6010) electrodes, then low hydro- gen vertical down electrodes offer 30%

and, prior todevelop- ing a welding offer- ing, the company had already accumulated many years of history in steelmaking. According to Höfer, the company was originally founded by Albert Böhler in 1870 andbegan tomanufactureweld- ing consumables in 1926. “Through a series of mergers and acquisitions, Böhler accumulated some of theworld’s best-in-class welding brands, including Thyssen, Böhler, UTP, Avesta Welding, Soudokay, Fontargen and Fileur. Today we have 41 branch offices in 28 coun- tries worldwide and a global network

Dominick Doyle of Gridweld in the UK demonstrates the use of Böhler cellulosic electrodes using a battery operated Fronius AccuPocket welding machine. Doyle, a founder and partner of Gridweld, a welding buggy supplier, has over 40 years of experience in the pipeline welding industry and has worked on a vast range of projects for major contractors.

“If preheating and interpass temperatures are correctly controlled, hydrogen cracking need never be a problem,” Höfer asserts.

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June 2015

AFRICAN FUSION