马弗管用BSTMUF601合金厚板焊接接头的组织特征与力学性能

Welding Joint Microstructure Characteristic and Mechanical Properties of Muffle Tube BSTMUF601 Alloy Thick Plate

对马弗管用BSTMUF601厚板焊接接头进行了金相组织分析、高温拉伸性能和硬度测试,研究了焊接接头组织特性与力学性能对材料使用性能的影响。结果表明,焊缝区为连续冷却的铸态组织,晶粒尺寸较小,晶界比较平直,晶粒表面以柱状晶的形式向焊缝中心生长,组织特征良好;热影响区受焊接热循环与温度梯度的影响,晶粒长大,性能有所下降;焊缝材料强度、硬度均大于母材区。焊缝区材料组织特征与力学性能整体优于母体材料,能够保证马弗管在高温服役环境下的可靠性。

Metallographic microstructure analysis, high temperature tensile properties and hardness testing were carried out on BSTMUF601 alloy thick plate welding joint of Muffle tube. The effects of microstructure and mechanical properties of welded joints on materials properties were studied. The results show that the welding zone is a continuous cooling as-cast structure with small grain size and flat grain boundary. The grain surface grows towards the welding center in the form of columnar crystal, and the structure features are good. The heat affected zone is affected by welding heat cycle and temperature gradient. When the grain grows, the performance will decrease.＇ The strength and hardness of welding joint materials are greater than that of base materials. The microstructure and mechanical properties of the welding joint area are better than the base materials, which can guarantee the reliability of muffle tube in high-temperature service environment.