摘要
在不预热的条件下,采用熔化极气体保护焊接方法对800 MPa低合金高强钢进行焊接,研究了焊接热输入对焊接接头的微观组织和性能的影响。结果表明:四种热输入条件下,焊缝区显微组织都有针状体素体组织,随着热输入增加,焊缝区的贝氏体组织减少,先共析铁素体和块状铁素体产生,针状铁素体呈现先增加后减少的趋势。随着热输入的增大,焊接接头的抗拉强度逐渐降低,而低温冲击韧性则先升高后下降。当线能量为14.66 k J/cm时,接头获得了良好的综合性能。
800 MPa grade high strength low alloy steel was welded by gas metal arc welding （GMAW） with different welding heat inputs. The effects of heat input on microstructure and properties of welded joint were investigated by SEM and mechanical properties tests. The results indicate that the microstructure of the four weld metal consist of acicular ferrite. With increasing heat input, the mount of bainite decreases, and the mount of acicular ferrite increases firstly and then decrease in weld area. When the heat input increases, the strength of the welded joints reduces gradually, while the low temperature impact toughness initially increases and then decreases. The optimum comprehensive strength and toughness properties can be obtained when the the heat input is 14.66 kJ/cm.
出处
《热加工工艺》
CSCD
北大核心
2015年第1期36-38,41,共4页
Hot Working Technology
基金
安徽省研究生"千人培养计划"项目(20130006)
安徽省大学生创新项目(AH201310360266)
关键词
低合金高强钢
热输入
组织
性能
high strength low alloy steel
heat input
microstrucmre
properties
