镀锌管螺纹加工方式对管牙显微组织和性能的影响

发布时间：2018-03-03 23:00

本文选题：滚压成形　切入点：切削　出处：《塑性工程学报》2017年06期 　论文类型：期刊论文

【摘要】：对采用滚压和切削两种成形方式加工的镀锌管螺纹管牙的显微组织、力学性能和极化曲线进行了对比研究。结果表明:滚压加工成形方式明显改善了管牙的表面质量,管牙表层和浅表层的显微组织因强烈塑性形变而明显细化且呈细长纤维状;严重的加工硬化使显微硬度显著升高,最高可达约240 HV;单管牙扣的最大抗拉力约为29.88 k N;此外,滚压加工方式使管牙表面镀锌层得以部分保留,从而提高了螺纹的耐蚀性。相比之下切削加工成形方式所加工的管牙表面粗糙,内部显微组织仍为等轴晶,表层和次表层显微硬度一般在184~194 HV之间,力学性能相对较差,单管牙扣的最大抗拉力为21.56 k N,仅为滚压成形的72.2%;管牙表面镀锌层被切除,螺纹耐蚀性显著下降。
[Abstract]:The microstructure, mechanical properties and polarization curves of zinc-plated tube thread teeth processed by rolling and cutting are compared. The results show that the surface quality of the tube teeth is obviously improved by rolling forming. The microstructures of the surface and shallow surfaces of the tube teeth are thinned and elongated due to strong plastic deformation; the microhardness is significantly increased by severe work hardening, up to about 240 HVT; the maximum tensile strength of the single tube buckle is about 29.88 kN; in addition, The zinc coating on the surface of the tube tooth can be partially retained by rolling machining, which improves the corrosion resistance of the thread. In contrast, the surface of the tube is rough and the internal microstructure is still equiaxed by cutting and forming. The microhardness of the surface and subsurface is generally between 1844 HV and the mechanical properties are relatively poor. The maximum tensile force of the single tube buckle is 21.56 KN, which is only 72.2% of the rolling forming, and the galvanized layer on the surface of the tube tooth is removed, and the corrosion resistance of the thread decreases significantly.
【作者单位】：武汉科技大学材料与冶金学院;武汉科技大学化学与化工学院;武汉市燃气热力规划设计院有限公司;
【分类号】：TG62

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