消除应力回火对高强钢HAZ韧性的影响

Effect of stress relief tempering on HAZ toughness in HSLA steels

关键词:  热影响区  韧性  应力

Key words:  HAZ  toughngss  stress

摘要:

研究了消除应力回火对高强钢HAZ韧性的影响。15MnMoVNRe钢HAZ韧性因析出造成二次硬化的Mo₂C、Mn₃N₂而下降。线能量越小,韧性相对损失越严重。HQ80钢类似,但除二次硬化外,还有高温回火脆性的影响。STE690钢HAZ600℃回火避开了脆性温度区,二次硬化损害韧性轻微,韧性改善是由于低温转变组织分解,析出Fe₃C,使晶格畸变减轻的缘故。线能量越大,回火后韧性改善程度越大。

Abstract:

In this paper,the effects of stress relief tempering on the HAZ toughness in HSLA steels are investigated.The results show that the secondary hardening decreases the HAZ impact toughness of 15MnMoVNRe steel after tempering.Moreover,the temper brittleness at high temperature is another more important cause to decrease the HAZ toughness fcr HQ80 steel.The smaller heat input,the more their relative loses of toughness are.As for STE609 steel,in spite of slight secondary hardening,the HAZ toughness is improved due to the dissolving of the structures transformed at low temperature and the decrease of distortion in the crystal lattice after tempering at 600℃.The large healt input,the mere obviously the toughness is improved.