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Combined Effect of Base Metal Dilution and Thermal Aging Conditions on the Corrosion Performance of Stainless Steel Claddings


Affiliations
1 Department of Mechanical Engineering, SLIET Longowal, Sangrur - 148106, Punjab, India
 

Objectives: Present work investigates the effects of base metal dilution and the thermal aging treatment on corrosion performance and strength of stainless steel claddings, fabricated by gas metal arc welding process. Methods/Statistical Analysis: Austenitic stainless steel AISI SS 316L was selected as the cladding material and low carbon steel as substrate for the present study. Experimental conditions were selected to achieve a varying degree of dilution of the deposit. Thermal aging treatment was given to specimens at 700ºC for 2 hours, 4 hours and 20 hours. The specimens were subjected to Double Loop Electrochemical Potentio Kinetic Reactivation (DLEPR), boiling nitric acid, and microhardness testing. Findings: Microhardness results of the clad deposits showed a continuous decrease in values from top of clad deposit to the base metal. However there is almost constant values of microhardness observed when it was measured along the clad deposit. Moreover the deposits with high dilution showed low microhardness values than that of low dilution clad beads. The low dilution clad deposits also performed better on testing the corrosion rate and degree of sensitization as compared to high dilution deposits. Corrosion rate measured from boiling nitric acid test showed a significant growth with increase of thermal aging time due to carbide precipitation. The corrosion rate of specimens in the as clad condition was as low as 0.19 mm/month which increased to 3.64 mm/month when sensitized for 20 hours at 700ºC. Degree of sensitization (DOS) calculated by DLEPR test is more significantly affected by the thermal aging treatment. The DOS values varied from as low as 2.47 % to high as 31% for as clad and sensitized conditions respectively. Application/Improvements: The present study can beneficially be adopted for weld overlay fabrications as it suggests the processing conditions to forecast the adequate strength and corrosion performance of components in similar service conditions.

Keywords

Corrosion Rate, Dilution, Degree of Sensitization, Microhardness, Thermal Aging.
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  • Combined Effect of Base Metal Dilution and Thermal Aging Conditions on the Corrosion Performance of Stainless Steel Claddings

Abstract Views: 139  |  PDF Views: 0

Authors

J. S. Gill
Department of Mechanical Engineering, SLIET Longowal, Sangrur - 148106, Punjab, India
A. S. Shahi
Department of Mechanical Engineering, SLIET Longowal, Sangrur - 148106, Punjab, India

Abstract


Objectives: Present work investigates the effects of base metal dilution and the thermal aging treatment on corrosion performance and strength of stainless steel claddings, fabricated by gas metal arc welding process. Methods/Statistical Analysis: Austenitic stainless steel AISI SS 316L was selected as the cladding material and low carbon steel as substrate for the present study. Experimental conditions were selected to achieve a varying degree of dilution of the deposit. Thermal aging treatment was given to specimens at 700ºC for 2 hours, 4 hours and 20 hours. The specimens were subjected to Double Loop Electrochemical Potentio Kinetic Reactivation (DLEPR), boiling nitric acid, and microhardness testing. Findings: Microhardness results of the clad deposits showed a continuous decrease in values from top of clad deposit to the base metal. However there is almost constant values of microhardness observed when it was measured along the clad deposit. Moreover the deposits with high dilution showed low microhardness values than that of low dilution clad beads. The low dilution clad deposits also performed better on testing the corrosion rate and degree of sensitization as compared to high dilution deposits. Corrosion rate measured from boiling nitric acid test showed a significant growth with increase of thermal aging time due to carbide precipitation. The corrosion rate of specimens in the as clad condition was as low as 0.19 mm/month which increased to 3.64 mm/month when sensitized for 20 hours at 700ºC. Degree of sensitization (DOS) calculated by DLEPR test is more significantly affected by the thermal aging treatment. The DOS values varied from as low as 2.47 % to high as 31% for as clad and sensitized conditions respectively. Application/Improvements: The present study can beneficially be adopted for weld overlay fabrications as it suggests the processing conditions to forecast the adequate strength and corrosion performance of components in similar service conditions.

Keywords


Corrosion Rate, Dilution, Degree of Sensitization, Microhardness, Thermal Aging.



DOI: https://doi.org/10.17485/ijst%2F2016%2Fv9i32%2F129144