Abstract The dissimilar welds joint of 2.25Cr-1Mo steel and lean duplex LDX2101 steel was prepared using the Gas Tungsten Arc Welding (GTAW) process and employing the Inconel 617 filler. The microstructural stability of the dissimilar welds joint (DWJ) was studied using the optical microscope and field emission scanning electron microscope (FESEM) for as-welded (AW) and post-weld heat treatment (PWHT) condition. The PWHT was employed at 760 °C (PW 1) and 810 °C (PW 2) for 2 h of duration. The application of the heat-treatment resulted in the formation of the soft zone at the interface of weld metal and HAZ in 2.25 Cr-1Mo side, i.e., low Cr side. The mechanical behavior of the DWJs was also studied for AW and PWHT condition. A measurable change in the width and hardness of the soft and hard zones was measured with an increase in PWHT temperature. For weld metal, the minimum average hardness was measured 237 HV in AW and a maximum of 248 HV for PW 2. In the AW condition, the average CIT of the weld metal was measured 46.5 ± 3.5 J, which meets the minimum recommended value as per EN 1557:1999 standards. The PWHT showed a drastic reduction in CIT and a minimum of 34 ± 3 J was measured for PW 2. The CIT of the 2.25Cr-1Mo HAZ (notch adjacent to fusion boundary includes the soft ferrite region) was measured 45 ± 5 J in AW and get increased drastically after the PWHT and maximum was measured for PW 2 (86 ± 5 J).

中文翻译：

---

2.25Cr-1Mo与贫双相LDX2101钢异种焊缝接头软区表征

摘要 采用气体钨极电弧焊(GTAW) 工艺，采用Inconel 617 填料制备2.25Cr-1Mo 钢和贫双相LDX2101 钢的异种焊缝接头。使用光学显微镜和场发射扫描电子显微镜 (FESEM) 在焊态 (AW) 和焊后热处理 (PWHT) 条件下研究异种焊缝接头 (DWJ) 的微观结构稳定性。PWHT 在 760 °C (PW 1) 和 810 °C (PW 2) 下持续 2 小时。热处理的应用导致在2.25 Cr-1Mo侧，即低Cr侧的焊缝金属和HAZ界面处形成软区。还研究了 AW 和 PWHT 条件下 DWJ 的机械行为。随着 PWHT 温度的增加，软硬区的宽度和硬度发生了可测量的变化。对于焊缝金属，AW 测得的最小平均硬度为 237 HV，PW 2 的最大平均硬度为 248 HV。 在 AW 条件下，测得的焊缝金属的平均 CIT 为 46.5 ± 3.5 J，满足最低推荐值：根据 EN 1557:1999 标准。PWHT 显示 CIT 显着降低，测得的 PW 2 的最小值为 34 ± 3 J。 2.25Cr-1Mo HAZ（与熔合边界相邻的凹口包括软铁素体区域）的 CIT 测量值为 45 ± 5 J AW 并在 PWHT 后急剧增加，并测量了 PW 2 (86 ± 5 J) 的最大值。