Intergranular corrosion is a problem that often occurs in welding stainless steel materials. Intergranular corrosion is caused by carbide precipitation which occurs at a temperature of 850 o C, causing a reduction in chromium content in the Heat Affected Zone (HAZ). The intergranular corrosion process can be controlled by the heat treatment method after the welding process. This study aims to study the effect of heat treatment on mechanical properties and intergranular corrosion resistance of SA240 TP316L material. The variation of heat treatment were divided into three solution treatment (ST), quenching treatment (QC), and non-treatment (NT). Mechanical properties testing using tensile test while corrosion resistance testing using linear polarization using H 2 SO 4 0.1 M solution. Morphology and metal composition in the HAZ area were analyzed using SEM-EDX. Tensile test results showed that welding with ST had the lowest yield strength, ultimate strength, and elongation values compared to specimens of 407.55 MPa, 599.33 MPa, and 44.53%. Corrosion test results found that welding with solution treatment has the lowest corrosion rate compared to specimens with quenching treatment (QC) and non treatment (NT). Corrosion rate in each ST, QC, and NT specimens was 0.90; 1.03; and 2.35 mmpy. The results showed that the solution treatment process can improve intergranular corrosion resistance.