热处理对09MnNiDR低温钢焊接接头组织及力学性能的影响
Effect of heat treatment on microstructure and mechanical properties of 09MnNiDR low temperature steel welded joint
张勇 1李如杨 2马青山 3胡效东3
作者信息
- 1. 山东百特机械设备有限公司,山东 临沂 276600
- 2. 山东华鲁恒升化工股份有限公司,山东 德州 253024
- 3. 山东科技大学机械电子工程学院,山东 青岛 266590
- 折叠
摘要
利用光学显微镜、拉伸试验机、冲击试验机和显微维氏硬度计对12 mm厚的09MnNiDR钢埋弧焊对接焊板经退火、正火和正火+回火处理后的组织、拉伸性能和低温冲击性能进行了分析.结果表明,正火处理可提高09MnNiDR钢焊接接头的强度,但与消应力退火相比会降低其韧性,而正火+回火处理后焊接接头兼具良好的塑性和韧性,这与焊缝处的M/A组元被不同程度分解以及热影响区的粒状贝氏体的演变有关.3种热处理方式(退火、正火、正火+回火)下,焊缝处的M/A组元被不同程度分解,使得冲击吸收能量提高.正火+回火的冲击吸收能量最高,相较焊态提升84％.与焊态相比,正火略微提高了焊缝和热影响区的硬度,而退火和正火+回火后硬度均降低.正火后热影响区中的粒状贝氏体有利于硬度提高,而回火后更均匀的组织使得焊接接头具有更好的韧性.
Abstract
Microstructure,tensile properties and low-temperature impact properties of a 12 mm thick U9MnNiDR steel submerged arc welding butt welded plate were analyzed by means of optical microscope,tensile testing machine,impact testing machine and micro Vickers hardness tester after annealing,normalizing and normalizing+tempering treatments.The results show that normalizing treatment can improve the strength of the 09MnNiDR steel welded joints,but compared with stress relief annealing,it reduces the toughness.After normalizing and tempering treatment,the welded joint has good plasticity and toughness,which is related to the decomposition of M/A components at the weld seam and the evolution of granular bainite in the heat affected zone.Under three heat treatment methods(annealing,normalizing,normalizing+tempering),the M/A components at the weld seam are decomposed to varying degrees,resulting in an increase of impact absorbed energy.The impact absorbed energy after normalizing and tempering is the highest,increasing by 84％compared to the welded.Compared with the welded joint,normalizing slightly increases the hardness of the weld zone and heat affected zone,while annealing and normalizing+tempering make the hardness reduce.The granular bainite in the heat affected zone after normalizing is beneficial for improving hardness,while the more uniform microstructure after tempering makes the welded joint obtain better toughness.
关键词
09MnNiDR低温钢/焊接接头/焊后热处理/显微组织/力学性能Key words
09MnNiDR low temperature steel/welded joint/post-weld heat treatment/microstructure/mechanical properties引用本文复制引用
出版年
2024
NETL
NSTL
万方数据