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| 摘要: |
| 采用MAG焊接工艺对转向架用P355NL1钢板进行焊接，研究了P355NL1钢焊接接头的微观组织形貌、硬度分布及室温力学性能。试验结果表明：焊缝组织主要是粗大板条状和块状的先共析铁素体、针状铁素体以及少量珠光体；热影响区的晶粒是大小不均匀的块状铁素体、针状铁素体。焊缝区硬度值分布在192～201 HV，热影响区的硬度最高可达220 HV。拉伸试样均断裂于母材处，其抗拉强度在518 MPa左右，断后伸长率平均为23.8%，P355NL1钢MAG焊接接头具有良好的强度和塑性。 |
| 关键词: 转向架 P355NL1钢 焊接接头 力学性能 |
| DOI： |
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| Study on microstructure and mechanical properties of welded jointsof P355NL1steel for bogie |
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Wei Kang1, Wang Xin2
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| Abstract: |
| P355NL1 steel plates used for train bogie were welded by using MAG welding process. Microstructure morphology, hardness distribution and mechanical properties at ambient temperature of P355NL1 steel welded joints were investigated. The experimental results show that, welded metal consists chiefly of coarse lath and massive proeutectoid ferrite, acicular ferrite and a few pearlite. In the heat affected zone, grains structure are block ferrite of uneven crystal sizes and acicular ferrite. The hardness values of welding seam area are distributed from 192 to 201 HV, but which can significantly increase up to 220 HV in the heat affected zone. The tensile specimens fracture at base metal with tensile strength of ～518 MPa, and the elongation rate is about 23.8%, which indicate that MAG welded joints of P355NL1 steel have reasonable strength and plasticity. |
| Key words: P355NL1 steel welded joints mechanical properties |
