Heat Input Influence on the Fatigue Life of Welds from Steel S460MC

Fine-grained steels belong to the progressive materials, which are increasingly used in the production of welded structures subjected to both static and dynamic loads. These are unalloyed or microalloyed steels hardened mainly by the grain-boundary strengthening mechanism. Such steels require specific welding procedures, especially in terms of the heat input value. At present, there are studies of the welding influence on the change of thermomechanically processed steels’ mechanical properties, however mainly under static loading. The paper is therefore focused on the assessment of the welding effect under dynamic loading of welded joints. In the experimental part was determined the influence of five different heat input values on the change of weld fatigue life. As a result, there is both determination of five S-N curves for the double-sided fillet welds from the thermomechanically processed fine-grained steel S460MC and the quantification of the main influences reducing the fatigue life of the joint.

Welding supports of fine-grained steel mobile platforms

The article presents the process of welding of steel movable platform supports. There is a growing demand for the welding of difficult-to-weld fine grain steels used in civil engineering and transport. An example of this could be the use of high-strength movable platform supports. The recently used material in the production of movable platform supports are fine-grained steels due to their high tensile strength of 1000 MPa. The joints formed using them, however, are characterized by much lower strength than the native material. In this article, the most appropriate parameters were selected for welding the movable platform supports made of difficult-to-weld fine-grained steel S960 MC.

ALDUR 900Q, QL

Aldur 900 steels (minimum yield strength of 900 MPa, or 131 ksi, for thicknesses up to 50 mm, or 2 in.) are a part of a family of waterquenched, high-strength, fine-grained steels that have excellent toughness at low temperatures. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on low temperature performance. Filing Code: SA-857. Producer or source: Voestalpine Grobblech GmbH.

ALDUR 700Q, QL, QL1

Aldur® 700 steels (minimum yield strength of 700 MPa, or 102 ksi, for thicknesses up to 50 mm, or 2 in.) are a part of a family of water-quenched, high-strength, fine-grained steels that have excellent toughness at low temperatures. This datasheet provides information on composition, physical properties, and tensile properties. Filing Code: SA-855. Producer or source: Voestalpine Grobblech GmbH.

ALDUR 620Q, QL, QL1

Aldur 620 steels (minimum yield strength of 620 MPa, or 90 ksi, for thicknesses up to 50 mm, or 2 in.) are a part family of water-quenched, high-strength, fine-grained steels that have excellent toughness at low temperatures. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on low temperature performance. Filing Code: SA-853. Producer or source: Voestalpine Grobblech GmbH.

ALDUR 550Q, QL, QL1

Aldur 550 steels (minimum yield strength of 550 MPa, or 80 ksi, for thicknesses up to 50 mm, or 2 in.) are a part family of water-quenched, high-strength, fine-grained steels that have excellent toughness at low temperatures. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on low temperature performance. Filing Code: SA-851. Producer or source: Voestalpine Grobblech GmbH.

ALDUR 500Q, QL, QL1

Aldur 500 steels (minimum yield strength of 500 MPa, or 73 ksi, for thicknesses up to 50 mm, or 2 in.) are a part family of water-quenched, high-strength, fine-grained steels that have excellent toughness at low temperatures. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on low temperature performance. Filing Code: SA-850. Producer or source: Voestalpine Grobblech GmbH.

TMP as an Effective Technique to Produce Ultra-Fine Grained Steels

In recent years, great attention is paid to the creation of methods andthe technological processes providing ultrafine-grained state of metal materials including submicro - and nanocrystalline ones. It pertains to structural components and to the phases constituting the particular metal or alloy. The main development in terms of obtaining bulk metallic materials received in recent years, various schemes of processing of metals by plastic deformation, which allows to realize the so-called severe plastic deformation (SPD). Such approach usually propose realization of large plastic strains, providing a well-developed fragmented substructure with the creation of high angle misorientation of the boundaries between the fragments of the substructure. The second direction in receiving finely divided state is to create technologies that provide a significant refinement of phase as a result of processing. The most effective way of achieving both the above effects applied to bulk metallic materials is Thermomechanical Processing (TMP), which can be used as a standalone technology or in combination of such methods as accumulation roll bonding (ARB) or other similar SPD methods. This paper discusses various methods of thermomechanical processing, based on the use of hot, warm and cold deformation, in various combinations applied to single and multiphase steels, ensuring the achievement of ultra-fine grained structure with elements of submicro - and nanostructures.

Influence of Grain Size on Work-Hardening Behavior in 12Cr Stainless Steel

Grain refinement is attracting attention as a strengthening method which does not depend on the alloying elements added to steels. Many reports have described the manufacturing methods and mechanical properties of ultra-fine grained steels. In ultra-fine grained steels, it is well known that yielding stress drastically increases in accordance with the Hall-Petch relationship, while uniform elongation significantly decreases. These tendencies imply that grain size affects not only yielding but also work-hardening behavior. However, the influence of grain size on work-hardening behavior has not been clearly understood. Therefore, in this study, we investigated the work-hardening behavior during tensile deformation of 12Cr stainless steel with various grain sizes. Grain refining was conducted by cold-rolling of annealed and quenched steel specimens, followed by recrystallization annealing. The grain size of the specimens decreased as the cold-rolling reduction rate increased. The minimum grain size obtained by this method was approximately 5 μm. With decreasing grain size, 0.2% proof stress increased and the strain which reached the plastic instability condition decreased. In the session, we report the dislocation accumulation behavior estimated by grain hardness and XRD and the dynamic recovery behavior assessed by the Kocks-Mecking model.