Evaluation of Mechanical Properties of S355J2C and HBW450 Materials Joined by MAG Welding Method Using Different Welding Groove Geometries

Abstract

In this study, S355J2C and Hardox (HBW450) sheets, which are used extensively in the manufacturing sector, were joined using the robotic MAG welding method by opening the V and X weld groove. Three different variable welding speeds were used in the joints, while other welding parameters were fixed. Microstructural examinations and mechanical tests were carried out on the welded materials produced. The microstructural examinations clearly showed the transition from the base metal to the weld metal and the formation of grains with dendritic structures directed towards the weld centre. The investigations showed that there was a relationship between welding speed and heat input and that hardness and tensile values increased with increasing welding speed. In the microhardness measurements, the lowest hardness values of all the test specimens were measured from the S355J2C base material. It was found that the hardness value of the weld metal was higher than the S355J2C base material and lower than the HBW450 base material, which would be the average of the hardness values of the two materials used. In addition, in the tensile tests, all the specimens failed from the S355J2C base material. As a result of the tests carried out, it was found that the different weld groove geometries did not play a very effective role in the mechanical values of the joints or the resulting microstructure.

Keywords

• s355jc2
• hardox
• MAG welding
• HBW450

Farklı Kaynak Ağzı Geometrileri Kullanılarak MAG Kaynak Yöntemiyle Birleştirilen S355J2C ve HBW450 Malzemelerin Mekanik Özelliklerinin Değerlendirilmesi

Abstract

Bu çalışmada, imalat sektöründe yoğun olarak kullanılan S355J2C ve Hardox (HBW450) levhalar V ve X kaynak ağızları açılarak robotik MAG kaynak yöntemi kullanılarak birleştirilmiştir. Birleştirmelerde diğer kaynak parametrelerinin sabit olduğu değişken 3 farklı kaynak hızı kullanılmıştır. Üretilen kaynaklı malzemelere mikroyapı incelemeleri ve mekanik testler uygulanmıştır. Mikroyapı incelemelerinde ana metallerden kaynak metaline geçiş net olarak görülmüş ve kaynak merkezine doğru yönlenmiş dendritik yapı içeren tanelerin oluştuğu tespit edilmiştir. Yapılan incelemeler sonrasında kaynak hızı ile ısı girdisi arasında bir ilişki olduğu artan kaynak hızı ile birlikte sertlik ve çekme değerlerinin de artış gösterdiği belirlenmiştir. Mikrosertlik ölçümlerinde tüm deney numunelerinde en düşük sertlik değerleri S355J2C ana malzemeden ölçülmüştür. Kaynak metalinin sertlik değeri kullanılan her iki malzemenin sertlik değerlerinin ortalaması olacak şekilde S355J2C ana malzemeden yüksek HBW450 ana malzemeden ise düşük olduğu belirlenmiştir. Ayrıca yapılan çekme testlerinde tüm numuneler S355J2C ana malzemeden kopmuştur. Uygulanan testler sonucunda farklı kaynak ağzı geometrilerinin birleştirmelerin mekanik değerleri üzerinde veya oluşan mikroyapıda fazlaca etkin bir rol oynamadığı tespit edilmiştir.

Keywords

• MAG kaynağı
• HBW450
• Hardox
• S355J2C

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