摘要
研究了焊后热处理保温时间对18MND5钢埋弧焊焊缝组织和力学性能的影响。结果表明,在高温1 h、24 h、40 h不同热处理保温时间下,焊缝金属的抗拉强度和屈服强度逐步减小,屈强比变化不明显,冲击吸收能量先提高后有所降低。随着焊后热处理保温时间的延长,焊缝金属中的C元素及合金元素由固溶强化转化为沉淀强化,使抗拉强度降低,冲击吸收能量提高。随着焊后热处理保温时间的过长,C元素和碳化物在晶界处聚集、偏析、粗化,导致抗拉强度和冲击吸收能量降低。
The effect of post welding heat treatment time on weld microstructure and mechanical properties of 18MND5 by SAW was studied. The result shows that with high temperature heat treatment for 1 h,24 h,40 h respectively,both tensile strength and toughness strength of the weld metal decrease at same time,but tensile and yield variation is less change; and the impact absorbing energy improves before it is reduced. Longer duration of post welding heat treatment,the elements of C and alloy in the weld metal by the solid solution strengthening into precipitation strengthening,which decrease tensile strength and increase impact absorbing energy.However,as it is too long,C elements and carbide are gathered,segregated and coarsened at grain boundary,which lead to decrease of tensile strength and impact absorbing energy.
出处
《机械制造文摘（焊接分册）》
2015年第6期17-20,共4页
Welding Digest of Machinery Manufacturing
基金
国家能源应用技术研究工程示范资助项目(NY20111201-1)
关键词
焊后热处理
18MND5钢
显微组织
力学性能
post weld heat treatment
18MND5 steel
microstructure
mechanical properties
