The Effects of the Electrode Type on Microstructure and Hardness of the RSW of DP600 Steel

Yıl 2020, , 181 - 193, 04.12.2020

Bilge Demir , Muhammed Elitaş , Hüseyin Karakuş

https://doi.org/10.17100/nevbiltek.403822

Öz

In
this paper, the effects of the electrode type on microstructure and hardness of
the resistance spot welded junctions of DP steel were studied. Commercial
galvanized DP sheet steel was used. Resistance spot welding (RSW), with
changing electrode type according to geometry, has been carried out with
constant weld time, weld current and weld pressure. Microstructure and hardness
are depending on materials properties and weld parameter particularly heat
input. Heat input is resulted from welding condition and parameters. Electrode
tip type effects welding contact and heat transfer during RSW. Results showed
that particularly spherical type electrode showed low heat input thus limited
microstructure changing at heat affected zone. This have on positive effect on
properties of the junctions. Depending on chemical composition of DP 600 harder
phases generally formed at weld zone.

Anahtar Kelimeler

DP, RSW, microstructure, hardness

Elektrot Tipinin Nokta Direnç Kaynaklı DP600 Çeliğinin Mikroyapı ve Sertliğine Etkileri

Öz

Bu
çalışmada, elektrot tipinin DP çeliğinin nokta direnç kaynaklı birleşimlerinin
mikroyapı ve sertliği üzerindeki etkileri incelenmiştir. Ticari galvanizli DP
sac çeliği kullanılmıştır. Nokta direnç kaynağı (NDK), geometriye göre değişen
elektrot tiplerinde, sabit kaynak süresi, kaynak akımı ve kaynak basıncında
gerçekleştirilmiştir. Mikroyapı ve sertlik malzeme özellikleri ve özellikle ısı
girdisi olmak üzere kaynak parametrelerine bağlıdır. Isı girdisi, kaynak
şartları ve parametrelerinden kaynaklanmaktadır. Elektrot uç tipi NDK süresince
kaynak teması ve ısı transferini etkilemektedir. Sonuçlar, özellikle küresel
tip elektrotun düşük ısı girdisi meydana getirdiğini, dolayısıyla ısıdan
etkilenen bölgede sınırlı mikroyapı değişiminin olduğunu göstermiştir. Bu durum,
birleşimlerin özellikleri üzerinde pozitif etkiye sahiptir. DP600 çeliğinin
kimyasal bileşimine bağlı olarak kaynak bölgesinde genellikle daha sert fazlar
meydana geldiği görülmüştür.   

Anahtar Kelimeler

DP, DP, NDK, mikroyapı, sertlik

Kaynakça

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