Mechanical Properties and Strengthening Contributions of AISI 316 LN Austenitic Stainless Steel Grade

The main goal of this contribution is to evaluate the mechanical properties, strengthening contributions and microstructure development of austenitic stainless steel AISI 316 LN with high nitrogen content in the states characterized as the initial state and the states after rolling with different thickness deformations. The initial state was represented by solution annealing (777 K/60 min). The deformation state was characterized by rolling thickness reductions carried out at ambient temperature (T = 295 K) with deformations in the range ε ∈ (0; 50> [%]. Studies of microstructures, mechanical properties and strengthening contributions before and after rolling were carried out. The initial state after solution annealing was as follows: offset yield strength R_p0.2 = 325 MPa, elongation A5 = 49% and diameter of grain size d = 214 μm. The state after ambient rolling with thickness deformation ε = 50% was as follows: R_p0.2 = 994 MPa, A5 = 4% and d = 64 μm. The maximum contribution to strengthening after rolling processing with 50% thickness deformation was dislocations (∆ R _{P0.2_DS} = 560 MPa) followed by twins (∆ R _{P0.2_DT} =140 MPa).