Open AccessAnalysis of T23 Steel Weld-Joint on the Stress Relaxation Crack at Medium Temperature
Author(s) -
Zhiqiang Sun,
Yuwei Wang,
Zhongbing Chen,
Yu Zhang,
Yongsheng Ding,
Heguo Zhu,
Shaohua Yin
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/730/1/012013
Subject(s) - materials science , welding , joint (building) , relaxation (psychology) , grain boundary , metallurgy , scanning electron microscope , crack closure , composite material , fracture mechanics , structural engineering , microstructure , psychology , social psychology , engineering
This paper issues a new type of reheat-crack of T23 steel weld which is deferent to the cracks occurred at higher temperature above 550 degree as literatures reported. The specimen to be studied taken from a unit with long service time is analyzed by means of metallographic, scanning electron microscopy and energy dispersive spectroscopy. When further in-depth analysis is carried out on the test results, we find that Ti (Al) -N compounds are precipitated at grain boundaries, promote the formation of cavities, and finally become crack. Although the temperature of the crack is only about 380 degree which is much lower than the reheat-crack sensitivite temperature limit of T23 steel, but we also regard this crack as a type of stress relaxation crack which is another form of reheat-crack in coarse grained region of T23 steel weld-joint under specific service environment.