Demand up for HIP components
Metso Powdermet, which produces metal components via the hot isostatic processing (HIP) method, has won its first order for an offshore customer in China. The China National Offshore Oil Corp. (CNOOC) ordered two barrel casings for Sulzer pumps, which the company supplied.
According to Göte Björman, product manager offshore, the CNOOC order helped Metso Powdermet in 2004 to its best ever year in terms of offshore turnover. Deliveries included swivels for four FPSOs -Baobab, Mutineer, Chinguetti,andAlvheim- all orders placed by Framo Engineering, hubs for Kristin, manifold sections for Rhum (both field developments off northwest Europe), wye pieces for Lobito/Tampoco, and valve bodies, and bonnets for other projects.
In addition, Statoil has ordered a further subsea manifold, due for delivery next year. This follows provision of a water injection manifold to the Heidrun development in 2003, for which Metso Powdermet received an award from the Metal Powder Industries Federation of the US.
The HIP method is well suited to the production of components such as swivels and highly configurated hubs with complex internal geometries, which are difficult to achieve through forging or casting.
A carbon steel mold or can is made in the desired shape, including internal pipe paths, and filled with powdered metal. The air is evacuated and the can sealed and placed in a hot isostatic press, where it is subjected for several hours to temperatures of around 1,150˚ C and pressures of around 1,000 bar in the presence of argon gas. It then undergoes heat treatment and quenching, following which the can is pickled away.
The can must be sealed efficiently, as ingress of argon would destroy the mechanical properties of the product. Through recent improvements in can fabrication, the rejection rate has been reduced to almost zero, in effect leading to increased production capacity, Björman says.
HIP products are completely dense, exhibit very even mechanical properties in all directions, and are near net-shape. This means they are very close to final dimensions, thereby reducing machinery requirements. Their fine microstructure makes them easy to inspect using ultrasonic techniques, and minimizes the risk of hydrogen-induced stress cracking.
The HIP process is suitable for use with a wide range of metals, including high alloyed steels, stainless steels, and super alloys. Metso Powdermet is now also qualified to the Norsok standard for the manufacture of products in F49, a super austenitic stainless steel with high impact values.•
For more information, contact Göte Björman, Metso Powdermet. Tel +46 220 34821, fax +46 220 33490, [email protected], www.powdermet.com.