核电用SA508-3钢大型锻件的内部裂纹缺陷分析及工艺优化

发布时间：2018-04-09 10:41

本文选题：SA-钢　切入点：大型锻件　出处：《锻压技术》2017年08期

【摘要】：SA508-3钢是目前大型核反应堆压力容器的主要材料,从材料成形角度提高SA508-3钢大型锻件整体性能从而提高零件安全性是大型铸锻件研究的重要方向。通过对传统锥板镦粗+平板旋转展平工艺成形的SA508-3钢大型锻件的超声波探伤密集型缺陷进行失效分析,得到缺陷为呈断续锯齿状的裂纹缺陷,缺陷产生的原因与微观偏析带引起的金属材料组织和性能不均有关。采用数值模拟方法,对传统工艺与锥板镦粗+胎模旋转展平新工艺进行比较分析。结果表明,采用新工艺时,锻件内部金属在三向压应力下发生大变形,可避免新裂纹产生,有利于已有闭合裂纹的焊合,锻件组织更加均匀。实际生产过程中,该方法可有效减少SA508-3钢大型锻件中的密集型裂纹缺陷。
[Abstract]:SA508-3 steel is the main material of large nuclear reactor pressure vessel at present. It is an important direction to improve the integral properties of large SA508-3 steel forgings and improve the safety of parts from the point of view of material forming.Based on the failure analysis of the ultrasonic flaw intensive defects of the large SA508-3 steel forgings formed by the traditional plate upsetting rotary flattening process, the defects are found to be intermittent jagged cracks.The causes of defects are related to the uneven microstructure and properties of metallic materials caused by microsegregation bands.A numerical simulation method was used to compare and analyze the traditional technology and the new technology of rotating flattening of cone plate upsetting tire die.The results show that when the new process is adopted, the metal inside the forging will deform greatly under the triaxial compressive stress, which can avoid the occurrence of new cracks, which is beneficial to the welding of the existing closed cracks, and the structure of the forgings is more uniform.The method can effectively reduce the dense crack defects in SA508-3 steel forgings.
【作者单位】：成都航空职业技术学院机电工程学院;重庆大学材料科学与工程学院;
【基金】：国家自然科学基金资助项目(51275543) 四川省教育厅科研资助项目(17ZB0035)
【分类号】：TG316;TM623.2

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