Study On The Susceptibility Of Reheat Cracking In 2.25Cr1Mo0.25V Steel

Due to their excellent properties, such as higher strength and hydrogen embrittlement resistance and hydrogen corrosion resistance at elevated temperature and so on,2.25Cr1Mo0.25V steel has replaced the traditional 2.25Cr1Mo steel to be the first choice for the manufacture of hydrogenation reactor. But the addition of Vanadium and Titanium and other strong carbide forming elements increase the reheat cracking susceptibility of welded joints during post weld heat treatments. In recent years, many 2.25Cr1Mo0.25V hydrogenation reactors have undergo reheat cracking during fabrication and service. But there is not an effective method to evaluate the susceptibility of reheat cracking in heat affected zone. In this paper, the reheat cracking problem of Chinese WuYang and Arcelor Mittal's 2.25Cr1Mo0.25V steel was studied, the main research contents were concluded as follows:(1) High temperature tension test at low strain rate and notched C-ring test were used to evaluate the susceptibility of reheat cracking in weld seam, the results showed that the welding seam is not sensitive to the reheat cracking.(2) Notched C-ring test was used to susceptibility of reheat cracking in CGHAZ and welding seam, and the results shows that the CGHAZ was more sensitive to reheat cracking than welding seam.(3) Notched C-ring test was proposed to evaluate the susceptibility of reheat cracking in CGHAZ, including sampling location, test procedure and evaluation criteria.(4) Gleeble thermal simulation method was used to evaluate the susceptibility of reheat cracking in CGHAZ of WuYang 2.25Cr1Mo0.25V steel under 3 kinds of heat input. And the evaluation criteria proposed in (3) were modified.