EN 10113/1-1993 Processability and surface quality of hot-rolled products of weldable fine-grained structural steels

，翻译如下：introduction Weldable fine-grained structural steels of thermomechanically rolled delivery conditions according to DIN EN 10113/1-1993 have a good processability and a good surface quality. These steels can be used for the production of welded components for the automotive and engineering industry, for the construction of buildings and containers and for machine construction applications. This paper gives an overview of the technology and the surface quality of these weldable fine-grained structural steels according to DIN EN 10113/1-1993. This includes an introduction of the delivery conditions and the processability as well as the properties of the surface after welding and the surface finish. Delivery conditions The weldable fine-grained structural steels according to DIN EN 10113/1-1993 are generally supplied in four qualities, namely S260NC, S355NC, S420NC and S460NC. These steels are supplied in the thermomechanically rolled delivery conditions. This means that the steels are delivered in the annealed condition with a ferritic-perlite grain size > 8. Depending on the steel quality and the thickness, steel sheets from 3 mm to 50 mm, in flat or curved shapes can be supplied. Processability The weldability of these steels is based on the appropriate chemical composition and fine grain size, regardless of the delivery conditions, i.e. whether hot-rolled or thermomechanically rolled. The thermomechanically rolled delivery condition reduces the risk of hardening cracks, while at the same time providing an improved formability and weldability. Properties of the surface after welding The weldable fine-grained structural steels of thermomechanically rolled delivery conditions according to DIN EN 10113/1-1993 show good results in terms of weldability. The fusion lines, hot cracking and cold cracking behaviour are very good. The fusion lines, which remain after welding, are all but invisible under normal circumstances. The results are also very good with regard to the surface roughness. The surface finish after welding is a smooth, almost glossy finish. The surface finish can be further improved with a subsequent heat treatment or by applying surface coating such as painting. Conclusion Weldable fine-grained structural steels of thermomechanically rolled delivery conditions according to DIN EN 10113/1-1993 have a good processability and a good surface quality. They can be used for various applications in the automotive and engineering industry, in machine construction and for the construction of buildings and containers. The weldability of these steels is very good and the fusion lines, hot cracking and cold cracking behaviour is also very good. The surface finish after welding is also very good and can be further improved with a subsequent heat treatment or by applying a surface coating.

Weldable fine grain steels with improved process performance of hot-rolled products and surface quality according to EN 10113/1-1993 are generally highly alloyed cold formable steels with a minimum yield strength of 420 MPa up to 700 MPa.

The main application area of these steels is structural steels and pressure vessels and also welding and hot stamping applications. As these steels are particularly suitable for these applications because of their good tensile and yield strengths, their tensile strength is usually considered as the main indicator of their suitability for visible or invisible welding.

The steels according to EN 10113/1-1993 show a tremendous improvement in their process behaviour compared to the reference standards. These include the following points:

-Improved formability

-Improved welding performance

-Improved surface finish

-Improved joint tightness

Due to their improved process performance, they are able to be welded with minimal preheating, are more cost-effective, and offer a better finish quality than standard steels.

The welding properties of these improved steels have also been improved by further modifications, such as additions of sulfur and molybdenum which improve their mechanical properties and also feedability during welding. The combination of improved process performance and improved welding properties makes these steels particularly suitable for structural or pressure vessel applications.

The improved process performance thus increases the productivity, reduces the amount of energy consumed, and leads to lower costs of production. This is the reason why the welding properties of these steels are considered superior to the reference standards.

In summary, the improved process performance and welding properties of the steels according to EN 10113/1-1993 make them a particularly suitable choice for structural or pressure vessel applications. These improved properties give them increased productivity, improved formability and enhanced welding performance, as well as improved surface finish and joint tightness. All these advantages make them a great choice for many welding applications and ensure the best product quality.