不同热处理状态9%Ni钢焊接接头的组织与韧性

Microstructure and toughness of welded joints for 9%Ni steel under different heat treatment

针对两种不同热处理工艺获得的9%Ni钢,采用手工立焊进行焊接并对其接头的组织和韧性进行了研究。经-196℃低温夏比V形缺口冲击试验、金相组织分析,结果表明,双相区热处理后的9%Ni钢,其接头的低温韧性均高于调质热处理9%Ni钢焊接接头的低温韧性。母材及焊接热影响区中的组织形态及逆转奥氏体的分布是决定接头低温韧性的主要因素;焊缝金属的低温韧性主要与焊条熔敷金属的成分有关。采用小热输入、多层焊、低的层间温度,都可使两种9%Ni钢焊接接头获得较高的低温冲击韧性。

The microstructure and low temperature toughness of welded joints of 9%Ni steels under two different heat treatment processes which were welded by manual vertical position were studied.The specimens were analyzed by -196℃Charpy V-notch impact test and optical microscope.The results show that the low temperature toughness of welded joint for 9%Ni steel under quenching and tempering was lower than that of addition intermediate quenching and tempering.The low temperature toughness of welded joint was dominated by the type of microstructure and distribution of reversal austenite.The low temperature toughness of weld metal was affected by the chemical composition of welding electrode. The higher low temperature toughness of 9%Ni steel welded joints can be obtained by using low heat input,multi-pass welding and low inter-pass temperature.