The aim of this research is to evaluate the local creep damage of various microstructures such as coarse grained heat affected zone （CGHAZ）, fine grained heat affected zone （FG- HAZ）, intercritical heat affected z...The aim of this research is to evaluate the local creep damage of various microstructures such as coarse grained heat affected zone （CGHAZ）, fine grained heat affected zone （FG- HAZ）, intercritical heat affected zone （ICHAZ） known as Type IV region, weld metal, and base metal of P92（9Cr-2W） steel weldment by small punch （SP） creep test at 600~ C. Also, to determine the weakest local part of the weldment, the effect of microstructures on creep rupture behavior in the weldment of P92 steel was studied. From the experimental results, the FGHAZ and Type IV region turned out to be very weak local parts of P92 weldment. Especially, the TYPE IV region showed the greatest displacement rate and had the shortest rupture life with many creep cavities widely spreaded in most of the region.展开更多
In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore...In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore, a small punch (SP) test was used.This test, which was originally developed to study irradiation damage using miniatursized specimens was performed at 77 and 4 K for solution treated and sensitized JN1 austenitic stainless steel, a candidate cryogenic structural material. The area under the load-deflection curve up to the maximum applied load in SP test was defined as the SP enerpy, to characterize the resistance to fracture. Although solution treated material exhibited ductile fracture mode with high SP enerpy, embrittlement behavior due to sensitization at 650-800°for 1-5 h was shown clearlg by SP test with brittle intergranular fracture and decreased SP enerpy. Comparison of the results obtained by SP test with those by fracture toughness test showed the usefulness of SP test for evaluation of sensitization induced embrittlement at cryogenic temperature. The re-sults obtained in this study can be very usefol in predicting the degradation due to welding and other processing in cryogenic materials.展开更多
The small punch test technique （SPT） was used to evaluate the mechanical properties of various materials and the basic method to test material tensile mechanics peqeormance from an inverse finite element （ FE） ari...The small punch test technique （SPT） was used to evaluate the mechanical properties of various materials and the basic method to test material tensile mechanics peqeormance from an inverse finite element （ FE） arithmetic with SPT was put forward. The research shows that specific tensile mechanical behavior and strain-stress distribution of each district of weld seam can be accurately determined by small punch test. Therefore, mechanical behavior of the inhomogeneous joint can be predicted by a numerical model. The simulation comes to good agreement with experimental data.展开更多
基金supported by KESRI(R-2005-7-021),which is funded by MOICE(Ministry of Commerce,Industry and Energy).
文摘The aim of this research is to evaluate the local creep damage of various microstructures such as coarse grained heat affected zone （CGHAZ）, fine grained heat affected zone （FG- HAZ）, intercritical heat affected zone （ICHAZ） known as Type IV region, weld metal, and base metal of P92（9Cr-2W） steel weldment by small punch （SP） creep test at 600~ C. Also, to determine the weakest local part of the weldment, the effect of microstructures on creep rupture behavior in the weldment of P92 steel was studied. From the experimental results, the FGHAZ and Type IV region turned out to be very weak local parts of P92 weldment. Especially, the TYPE IV region showed the greatest displacement rate and had the shortest rupture life with many creep cavities widely spreaded in most of the region.
文摘In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore, a small punch (SP) test was used.This test, which was originally developed to study irradiation damage using miniatursized specimens was performed at 77 and 4 K for solution treated and sensitized JN1 austenitic stainless steel, a candidate cryogenic structural material. The area under the load-deflection curve up to the maximum applied load in SP test was defined as the SP enerpy, to characterize the resistance to fracture. Although solution treated material exhibited ductile fracture mode with high SP enerpy, embrittlement behavior due to sensitization at 650-800°for 1-5 h was shown clearlg by SP test with brittle intergranular fracture and decreased SP enerpy. Comparison of the results obtained by SP test with those by fracture toughness test showed the usefulness of SP test for evaluation of sensitization induced embrittlement at cryogenic temperature. The re-sults obtained in this study can be very usefol in predicting the degradation due to welding and other processing in cryogenic materials.
文摘The small punch test technique （SPT） was used to evaluate the mechanical properties of various materials and the basic method to test material tensile mechanics peqeormance from an inverse finite element （ FE） arithmetic with SPT was put forward. The research shows that specific tensile mechanical behavior and strain-stress distribution of each district of weld seam can be accurately determined by small punch test. Therefore, mechanical behavior of the inhomogeneous joint can be predicted by a numerical model. The simulation comes to good agreement with experimental data.
