Independency of Elasticity on Residual Stress of Room Temperature Rolled Stainless Steel 304 Plates for Structure Materials

Parikin, Parikin
Allen, David

Makara Journal of Technology
Vol. 19, No. 3

Mechanical strengths of materials are widely expected in general constructions of any building. These properties depend on its formation (cold/hot forming) during fabrication. This research was carried out on cold-rolled stainless steel (SS) 304 plates, which were deformed to 0, 34, 84, and 152% reduction in thickness. The tests were conducted using Vickers method. Ultra micro indentation system (UMIS) 2000 was used to determine the mechanical properties of the material, i.e.: hardness, modulus elasticity, and residual stresses. The microstructures showed lengthening outcropping due to stress corrosion cracking for all specimens. It was found that the tensile residual stress in a specimen was maximum, reaching 442 MPa, for a sample reducing 34% in thickness and minimum; and about 10 MPa for a 196% sample. The quantities showed that the biggest residual stress caused lowering of the proportional limit of material in stress-strain curves. The proportional modulus elasticity varied between 187 GPa and of about 215 GPa and was free from residual stresses.