TPT May 2019

AR T I C L E

SMS group

Microstructure, centrifugally cast composite pipe, material transition after forging

Titanium pipe, Ti Gr2, 277 x 32mm, ratio of expansion 3.5

Inhomogeneous block temperature after piercing

The former cast structure has completely dissolved. High- alloyed centrifugally cast shells made of material 1.4404 also behave similarly. Pipes made of centrifugal composite casting were forged for the first time using this technology. The outer shell consisted of low-alloyed steel 42CrMo4 and the inner part of high-alloyed austenitic steel 1.4404. The 283 x 36mm forged pipe (ratio of extension 3.5) is characterised by a faultless material transition. The former cast structure has completely dissolved. With this “step-forging” process it is possible to selectively vary the outer pipe diameter. For different inner diameters within a pipe shaping mandrels can be used. Future outlook Due to rising energy costs, continuous development of the SMX hydraulic radial forging machine is currently focusing on a reduction in energy consumption. Corresponding concepts were developed. Whether temperature- and pressure-resistant tubes and pipes for power plants are needed, or anti-corrosive oilfield tubulars or wear-proof mechanical tubing, the new SMX pipe forging line can accommodate all the requirements of the customer. SMS group SMS group is a leading company in the world of metals. As a family-owned business headquartered in Germany, quality and innovation are its core principles. Fast and flexible, the company develops individual and modular solutions – whether for the design of a new plant, modernisation, digitalisation or life cycle services.

Forged pipes 277 x 32mm, 42CrMo4, ratio of extension 4 (left) and 302 x 42mm, 1.4404, ratio of extension 2.5 made of centrifugally cast shells (right)

Pipe por tfolio For an SMX 800/18MN the entire pipe portfolio includes pipes with manufacturing diameters from 150 to 500mm and wall thicknesses between 27 and 100mm for manufacturing lengths of up to 10m. Even larger pipes can be produced on an SMX 1100/22 MN with a tool opening of 1,100mm and a forging power of 22 meganewtons. Depending on the intended use, the outer and/or inner pipe surface must be machined after forging. Even large wall thickness tolerances of ±15mm, which may occur on an open-die forging press during shell piercing, are reduced to much smaller eccentricities between 1 and 2.6mm when pipes are forged on an SMX. Demanding materials that cause problems during seamless pipe rolling, or that cannot be rolled during the cross-rolling process due to defect formations, can be forged perfectly on hydraulic radial forging machines of the SMX type. On the SMX, for example, pipes of nickel material UNS N 08028 were forged containing more than 30 per cent nickel. These pipes are employed in the chemical and petrochemical industry as well as in oil and gas exploration in acid gas fields. Titanium pipes and ratios of extension up to 4 can also be forged without problems at forging temperatures between 800 and 830°C. Furthermore, pipes can be forged from pre-machined centrifugally cast shells. The surface of the forged pipes is excellent and the microstructure after forging shows a fine bainite with grain size 8 to 9 (accuracy is to ASTM E 112).

SMS group – Germany Tel: +49 211 881 0 Fax: +49 211 881 4902 Website: www.sms-group.com

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MAY 2019