This　paper　explores　the　effects　of　residual　stresses　on　the　pitting　corrosion　of　304　stainless　steel　pipes.　The　open　circuit　potential(OCP),　polarization　test,　electrochemical　impedance　spectroscopy(EIS),　Mott-Schottky　and　other　methods　are　used　to　study　the　effects　of　stresses　and　Cl-　concentration　on　the　corrosion　of　cold-bent　304　stainless　steel　elbows.　The　pitting　corrosion　and　passive　film　characteristics　of　different　parts　of　the　elbow　in　100　and　1　000　mg/L　Cl-　solution　were　tested.　How　the　stresses　and　Cl-concentration　affect　the　pitting　corrosion　of　stainless　steel　and　the　corresponding　corrosion　mechanism　were　analyzed.　The　results　show　that　the　residual　stresses　on　the　U-bend　tensile　surface　and　compression　surface　of　304　stainless　steel　after　cold　machining　are　tensile　and　compressive　stresses　respectively,　and　that　there　is　almost　no　stress　on　the　undeformed　straight　pipe.　The　corrosion　test　shows　that　when　the　Cl-　concentration　is　100　mg/L,　the　residual　stress　will　enhance　the　ability　of　stainless　steel　to　resist　Cl-　pitting　corrosion　and　reduce　the　carrier　concentration　of　the　passivation　film.　The　effects　of　tensile　stress　are　stronger　than　those　of　compressive　stress　and　the　maximum　pit　depth　is　80.426　μm).　When　the　Cl-　concentration　is　1　000　mg/L,　both　tensile　and　compressive　stresses　reduce　the　ability　of　stainless　steel　to　resist　Cl-　pitting　corrosion,　and　the　pit　size　at　the　tensile　stress　is　the　greatest　under　the　same　concentration　condition(117.956　μm).　©　2022　Xi＇an　Jiaotong　University.　All　rights　reserved.