Hot-rolled wide strip for production of large diameter,heavy gauged(up to 19 mm) helical line pipe grade X80 was a priority development over the last three years.Microstructure,texture and mechanical properties of str...Hot-rolled wide strip for production of large diameter,heavy gauged(up to 19 mm) helical line pipe grade X80 was a priority development over the last three years.Microstructure,texture and mechanical properties of strips have been characterised.Also the welding conditions have been simulated.The favourable microstructure is achieved by the proper selection of an appropriate chemical composition of low carbon content and increased niobium micro alloying in combination with suitable strictly controlled hot-rolling parameters.The addition of niobium in combination with the adjustment of other alloying elements increases the recrystallisation stop temperature and thus makes it possible to apply a high temperature processing(HTP) concept.The homogeneous bainitic microstructure across the strip gauge is then formed during accelerated cooling on the run-out table of the hot-rolling mill.All results indicated excellent properties of these hot strips which make it suitable for spiral pipes of grade X80 for example 18.9mm×Φ1 220 mm at dimension.展开更多
Background:Bullets recovered from the crime scenes often undergo severe deformation,which leads to the loss of important morphological features,posing significant challenges to traditional examination methods.Aims and...Background:Bullets recovered from the crime scenes often undergo severe deformation,which leads to the loss of important morphological features,posing significant challenges to traditional examination methods.Aims and Objectives:The respective study explores the novel application of high-resolution 3d scanning and digital superimposition.These techniques are analyzed as alternatives to conventional methods for linking the deformed bullets and conventional bullets,proposing a foundation for future standard protocols.Materials and Methods:A total of 20 projectiles-9 mm×19 mm,7.62 mm×39 mm,and 7.62 mm×51 mm calibers were test-fired at target surfaces from distances ranging between 5 and 10 m from the muzzle.Each projectile was 3d scanned and digitally compared with reference samples of the same caliber post-segregation-based physical matrices.Using the surface scanner and then compared with the same caliber reference standards,followed by superimposition.The methodology involved systematic documentation and segregation of samples based on their physical characteristics.Accurate 3d models were recorded and aligned with reference samples following a degree of matching based on the color-coded criteria.This approach enabled minute-level analysis and overcame the limitation of manual errors that occur via visual inspection.Results:The results demonstrated effective linkage,suggesting valuable insights such as firing direction,range,and impact dynamics.9 mm×19 mm caliber yielded the highest match rate out of the total population when superimposed at the base periphery,and a potential match was achieved by the superimposition technique that used color mapping to display overlapping surfaces.The x-ray images captured within the software confirmed accuracy in bullet alignment while superimposition,hence validating the methodology’s precision.Conclusion:The methodology represents a novel approach in the field of forensic science.展开更多
文摘Hot-rolled wide strip for production of large diameter,heavy gauged(up to 19 mm) helical line pipe grade X80 was a priority development over the last three years.Microstructure,texture and mechanical properties of strips have been characterised.Also the welding conditions have been simulated.The favourable microstructure is achieved by the proper selection of an appropriate chemical composition of low carbon content and increased niobium micro alloying in combination with suitable strictly controlled hot-rolling parameters.The addition of niobium in combination with the adjustment of other alloying elements increases the recrystallisation stop temperature and thus makes it possible to apply a high temperature processing(HTP) concept.The homogeneous bainitic microstructure across the strip gauge is then formed during accelerated cooling on the run-out table of the hot-rolling mill.All results indicated excellent properties of these hot strips which make it suitable for spiral pipes of grade X80 for example 18.9mm×Φ1 220 mm at dimension.
文摘Background:Bullets recovered from the crime scenes often undergo severe deformation,which leads to the loss of important morphological features,posing significant challenges to traditional examination methods.Aims and Objectives:The respective study explores the novel application of high-resolution 3d scanning and digital superimposition.These techniques are analyzed as alternatives to conventional methods for linking the deformed bullets and conventional bullets,proposing a foundation for future standard protocols.Materials and Methods:A total of 20 projectiles-9 mm×19 mm,7.62 mm×39 mm,and 7.62 mm×51 mm calibers were test-fired at target surfaces from distances ranging between 5 and 10 m from the muzzle.Each projectile was 3d scanned and digitally compared with reference samples of the same caliber post-segregation-based physical matrices.Using the surface scanner and then compared with the same caliber reference standards,followed by superimposition.The methodology involved systematic documentation and segregation of samples based on their physical characteristics.Accurate 3d models were recorded and aligned with reference samples following a degree of matching based on the color-coded criteria.This approach enabled minute-level analysis and overcame the limitation of manual errors that occur via visual inspection.Results:The results demonstrated effective linkage,suggesting valuable insights such as firing direction,range,and impact dynamics.9 mm×19 mm caliber yielded the highest match rate out of the total population when superimposed at the base periphery,and a potential match was achieved by the superimposition technique that used color mapping to display overlapping surfaces.The x-ray images captured within the software confirmed accuracy in bullet alignment while superimposition,hence validating the methodology’s precision.Conclusion:The methodology represents a novel approach in the field of forensic science.
