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The objective of this study is to investigate the probability of mechanical trimming using hot half-trimming in actual hot stamping process. Hot half-trimmed part can be inaccurately positioned on mechanical trimming die by relatively low accuracy of automatic transferring system or manual way, leading to the change of clearance in mechanical trimming. Taking into account this position error, a suitable operation window for trimming of flat and inclined part was constructed by FE-simulation and then was verified by experiment. It was determined from the operation window that effective mechanical trimming for both flat and inclined part can be performed successfully with hot half-trimming depth of 1.0 mm in hot half-trimming and clearance between 0.1 mm and 0.124 mm in subsequent mechanical trimming, without regard to position error.

The purpose of this study is to investigate the elastic-plastic behavior of inclusions, i.e. SiO2 particles, in cold drawn wire using reverse analysis and nanoindentation test. First, the nanoindentation tests were performed to obtain indentation load P – penetration depth h curves. Second, the reverse analysis which is consisted of various dimensionless functions including change in E∗/σr, Wp/Wt and n was used to extract the elastic-plastic properties of the indented inclusions and metals from indentation responses. To verify the accuracy of calculated properties, uniaxial tensile tests were performed for different materials which are AISI 1045 and AISI 1080. Results (E, σy, n) of tensile tests for each material were also compared with those of nanoindentation tests.