Duplex stainless steels (DSSs) are prone to formation of various secondary phases in their microstructure upon exposure to high temperatures which can lead to degradation in their engineering performance. The present work was aimed to study the effect of a wide range of isothermal treatments (475°–1050 °C) on the impact toughness and corrosion resistance besides microstructure, ferrite content and microhardness of gas tungsten arc (GTA) welded 2205 DSS. It was observed that the isothermal exposure at 850 °C for 2 h led to maximum ferrite content reduction, imparted maximum hardening, caused maximum embrittlement of the weld metal (203 J → 2 J) and HAZ (204 J → 3 J) regions of the weldment besides causing maximum degradation in the pitting corrosion resistance. Corresponding to the aging condition of 475 °C/20 h, reduction in the ferrite content was not much, however, a significant increase in the microhardness along with severe loss in the toughness of the weld metal (203 J → 6 J) occurred, but the HAZ region was relatively tolerant (204 J → 54 J) against loss of toughness. In general, impact and corrosion properties were highly sensitive to degradation at 850 °C. Hence it can be inferred that the amount of ferrite content reduction cannot be directly correlated with the extent of hardening, decrease in the toughness and corrosion resistance; as such, changes will be primarily governed by the type of secondary precipitation which is temperature and exposure duration-dependent in the case of DSS welds.

双相不锈钢（DSS）暴露于高温下时易于在其微观结构中形成各种次级相，这可能导致其工程性能下降。本工作旨在研究各种等温处理（475°-1050°C）对2205 DSS焊接钨极氩弧焊（GTA）的组织，铁素体含量和显微硬度以及冲击韧性和耐蚀性的影响。观察到在850°C下等温暴露2 h导致最大的铁素体含量减少，最大程度的硬化，引起焊缝金属（203 J→2 J）和HAZ（204 J→3 J）区域的最大脆化。除了使焊点耐蚀性最大程度降低外，焊件也是如此。对应于475°C / 20 h的老化条件，铁素体含量的减少并不多，但是，显微硬度显着增加，同时焊缝金属的韧性严重降低（203 J→6 J），但热影响区相对耐受（204 J→54 J）。 ）防止韧性降低。通常，冲击和腐蚀性能对850°C下的降解高度敏感。因此可以推断出，铁素体含量的减少量不能与硬化程度，韧性和耐腐蚀性的降低直接相关。因此，对于DSS焊缝，变化将主要取决于二次沉淀的类型，二次沉淀的类型取决于温度和暴露时间。但是HAZ区域对韧性损失的耐受性相对较高（204 J→54 J）。通常，冲击和腐蚀性能对850°C下的降解高度敏感。因此可以推断出，铁素体含量的减少量不能与硬化程度，韧性和耐腐蚀性的降低直接相关。因此，对于DSS焊缝，变化将主要取决于二次沉淀的类型，二次沉淀的类型取决于温度和暴露时间。但是HAZ区域对韧性损失的耐受性相对较高（204 J→54 J）。通常，冲击和腐蚀性能对850°C下的降解高度敏感。因此可以推断出，铁素体含量的减少量不能与硬化程度，韧性和耐腐蚀性的降低直接相关。因此，对于DSS焊缝，变化将主要取决于二次沉淀的类型，二次沉淀的类型取决于温度和暴露时间。降低韧性和耐腐蚀性；因此，对于DSS焊缝，变化将主要取决于二次沉淀的类型，二次沉淀的类型取决于温度和暴露时间。降低韧性和耐腐蚀性；因此，对于DSS焊缝，变化将主要取决于二次沉淀的类型，二次沉淀的类型取决于温度和暴露时间。