细直径YG5FA硬质合金/45Cr钢储能焊工艺分析

Microstructure of small diameter cemented carbide YG5FA/45Cr steel joined by capacitor discharge welding

关键词:  细直径硬质合金  45Cr钢  储能焊  界面组织

Key words:  small diameter cemented carbide  45Cr steel  capacitor discharge welding  interface microstructure.

摘要:

应用微型储能焊机对φ1.5 mm超细颗粒硬质合金YG5FA和45Cr合金钢进行对焊,研究了结合界面的结构特征、组织形态及结合机制,分析了焊接参数对接头质量的影响。结果表明,储能焊能够实现超细颗粒硬质合金的快速凝固焊接,有效防止界面反应,获得的焊接接头组织细小致密,硬质合金组织无粗化迹象。裂纹是硬质合金储能焊接头的主要缺陷,具有典型的脆断特征和延迟特性。焊后进行350℃保温30 min的去应力处理,即可有效地预防裂纹的产生。

Abstract:

The butt welding of φ1.5 mm ultrafine grain cemented carbide YG5FA and 45Cr steel was performed by using a micro-type capacitor discharge welding machine.The structure characteristic of weld interface, microstructural morphology and joining mechanism were investigated, and the effect of welding parameters on joint quality is also analyzed.The results show that the capacitor discharge welding can realize the rapid solidification joining of the cemented carbides.This method can efficiently prevent the interface reaction and the joint with fine and dense microstructure is obtained. The microstructure of cemented carbide has no coarsening appearance. The crack is the main welding defect in cemented carbide joint, which has typical brittle and delay characteristic.the welding crack could be effectually eliminated by annealing of 350℃/30 min after welding.