20th International Forgemasters Meeting - IFM 2017

3.5%NiCrMoV steel has been widely used for generator rotor forgings for the purpose of obtaining high strength, toughness and magnetic permeability. Although the added alloy elements are important to achieve specified mechanical properties, reducing the amount of alloy elements is also important to contribute to natural resource savings and cost savings. In this study, the effects of Ni and Cr...

Currently ferritic heat resistant steels are mainly used for large industrial gas turbine disks because large disks made of ferritic heat resistant steels can be produced easily. On the other hand, it is well known that Ni based supperalloys such as Alloy706, Alloy718, Waspaloy, etc., on have much higher strength at elevated temperatures than ferritic heat resistant steels. Alloy718 has very...

Over decades Böhler Special Steel has been a full package supplier of customized high quality special steels and forgings. Böhler Special Steel fosters close relationships to plant manufacturers with the aim to provide products ahead of its time. This paper provides some results of our research activities to raise the operating temperatures of 9% Cr steels from 625 °C (1157 °F) to 650 °C (1202...

With the rapid development of economic, it is urgently need to develop coal-fired power generation technology of further increased value of steam parameters in China. National 700℃ USC coal-fired power generation technology innovation consortium has been founded to develop the 700℃ USC technology and key components of steam turbine in 2010. All the forgings used for 700℃ and higher steam...

Our company manufactures forged duplex and super duplex stainless steel products. These materials are called ASTM A182 F51, F53 and F55. These have high strength and high corrosion resistance. Super duplex stainless steels (SDSS) are by definition a duplex stainless steel with a pitting corrosion equivalent (PRE) > 40, where PRE = %Cr + 3.3x %Mo + 16x %N. So these are used injection pumps with...

The objective of this study is to develop the spent nuclear fuel shipping cask shell material and welding rods with high toughness at very low temperature. Recently, in Korea, The demand of shipping cask has been increased to transfer spent nuclear fuel and nuclear waste to an interim facility and store safely due to the limitation of the storage space inside nuclear power plant. The shipping...

In recent years, as part of measures against global warming, utilization of renewable energy has been increasing to reduce CO2 emission. Especially, geothermal power generation, which can supply large scale power steadily, has been being developed around the world, and there is a growing demand for large rotor forgings for large scale geothermal power generation. Japan Casting & Forging...

A digital engineering system using finite element (FE) analysis was developed in order to optimized forging and rolling process for obtaining an adequate microstructure in large-scale forged and rolled products. For precise prediction of changes in microstructure during forging and rolling, the re-crystallization behavior should be investigate carefully. Ni-based super alloys are usually...

Low thermal expansion superalloys are thought to be candidates to reduce the clearance between some parts in turbo machines in order to improve the efficiency. Alloy903, Alloy909, HRA9291), etc. which were previously developed are well known as commercial low thermal expansion superalloys. The low thermal expansion properties of these alloys are obtained by the mechanism to control the thermal...

Recently, Co-Al-W alloys with a new γ’ phase consisting of Co₃(Al,W) have been found. Since the Co-Al-W-based alloys show the γ/γ’ microstructure similar to the Ni-based superalloys and flow stress anomaly, it is expected that the Co₃(Al,W) strengthening Co-based superalloys would be able to be applied to higher temperature applications. However, the hot workability is...

Ni-base superalloy LTES700R turbine rotors for advanced-ultra supercritical (A-USC) power generation was produced, and their microstructure, tensile, impact, and creep properties were evaluated. 10-ton class rotor forging was successfully produced through the double melting technique, which is the vacuum induction melting (VIM) followed by the electroslag remelting (ESR), and free forging with...

The most significant outcome of the European COST programs (1983 – 2009) was the development of creep resistant 9-10%-Cr-steels for 600°C and 620°C application temperature. COST FB2 steel alloyed with boron is currently the best available material for turbine shafts subjected to steam temperatures up to 620°C and meanwhile introduced in production for application in commercial power...

Duplex stainless steels are in good combination with strength, ductility and corrosion resistance. For this reason, duplex stainless steels are considered as excellent choices for various industrial applications such as oil extraction, paper manufacturing and other chemical industries. From the industrial point of view, the hot deformation of these steels has drawn much attention due to cracks...

During pressure test of a huge hydro power plant; embritteled weld material caused a catastrophic fracture of the closure head of a new penstock. Temper embrittlement (TE) in weldings of high strength steel type S 690.was identified as basic cause of theobserved failure. TE was caused by application of an unusual slow cooling rate during post weld heat treatment. A procedure, characterized by...

Forging temperature is an important parameter to be defined in the forging process planning, because the final mechanical properties are directly influenced by this process temperature. In this study the AISI 4130 engineering steel, used for flexible tubes connectors in oil and gas industry, was investigated concerning the forging and heat treatment processes. Ingots up to 18 ton were forged...

The ultrasonic technique is the main non-destructive testing (NDT) method for the inspection of large forgings. With this technique, it is also possible to obtain information about microstructural features, which is very important because it gives the possibility to easily check the quality of processes during all the production cycle. In this paper, the relationship between some...

Because tool steels are widely employed in industrial as machining tools and dies. Excellent mechanical properties, such as hardness, toughness and strength, are the most important criteria in evaluating tool steels. As a coarse dendritic structure with bulk precipitates owing to segregation causing embrittlement in the interdendritic regions, grain refinement and the uniform distribution of...