道间温度对10CrNi5MoV钢气体保护焊接头力学性能的影响

通过屈服强度和冲击韧性测试、组织分析,研究了两种焊接热输入条件下道间温度对10CrNi5MoV钢气体保护焊接头力学性能的影响。结果表明,随着道间温度从40℃提高到300℃,焊接热输入为8 kJ/cm和18 kJ/cm的焊缝金属屈服强度分别从868 MPa和855 MPa单调下降至728 MPa和693 MPa,-50℃冲击韧性分别从70 J和69 J升高至117 J和72 J(道间温度分别为200℃和100℃),然后降低至67 J和43 J;焊缝金属的组织差异是不同道间温度下焊接接头力学性能不同的原因。随着道间温度从40℃提高到300℃,焊缝金属中马氏体组织逐渐消失,粒状贝氏体组织逐渐增多,针状铁素体组织比例先增加再减少,含量最高时的道间温度与冲击韧性峰值水平相一致。

Effect of Interpass Temperature on Mechanical Property of Gas Shielded Welding Joint to 10CrNi5MoV Steel

Effect of interpass temperature on mechanical property of 10CrNi5MoV steel gas shielded welding joint was investigated in two different energy input by yield strength,impact toughness testing and tissue analysis. The results indicated that when the energy input was 8 kJ / cm and 18 kJ / cm,the yield strength of weld metal monotonic decreased from 868 MPa and 855 MPa to 728 MPa and 693 MPa respectively,impact toughness at- 50 ℃ of weld metal rised from 70 J and 69 J to 117 J and 72 J( interpass temperature was 200 ℃ and 100 ℃ respectively),then reduced to 67 J and 43 J. The difference in the tissue made the mechanical property changed with the interpass temperature elevated. With interpass temperature rised from 40 ℃ to 300 ℃,the content of martensite structure in weld metal gradually disappeared,granular bainite structure gradually increased,acicular ferrite structure increased first,and then decreased. The interpass temperature corresponded to the peak of acicular ferrite structure content was consistent to the peak of the impact toughness.