The effect of W on the microstructure and the mechanical properties of ultrahigh strength low alloy steels was carried out. The microstructure of 30Cr3Si2Mn2NiMoNb and 30Cr3Si2Mn2NiMoNbW steels under quenched conditio...The effect of W on the microstructure and the mechanical properties of ultrahigh strength low alloy steels was carried out. The microstructure of 30Cr3Si2Mn2NiMoNb and 30Cr3Si2Mn2NiMoNbW steels under quenched conditions were investigated by metallographic microscope, scanning electron microscope （SEM）, X-ray diffrac- tion （XRD）, and transmission electron microscope （TEM）. Thermodynamic cal- culation was also conducted. The results showed that the addition of W made undissolved carbides more and finer, which exerted strong pinning force on migrat- ing packet boundary and improved tensile strength significantly. M6C particles in 30Cr3Si2Mn2NiMoNb steel were disappeared above 1193 K, while the M6C particles in 30Cr3Si2Mn2NiMoNbW steel were disappeared above 1253 K, the calculation results were in agreement with the experimental.展开更多
Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg...Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg-y Si-z Ti alloys have been investigated.The analysis of variance shows that both Mg and Si apparently infl uence the tensile properties of the alloys,while Ti does not.The tensile mechanical properties are comprehensively infl uenced by the amount of eutectic phase(α-Al+Mg2Si),the average grain size,and the content of Mg dissolved intoα-Al matrix.The optimized alloy is Al-7.49 Mg-3.08 Si-0.01 Ti(wt%),which exhibits tensile yield strength of 219 MPa,ultimate tensile strength of 401 MPa,and elongation of 10.5%.Furthermore,contour maps,showing the relationship among compositions,microstructure characteristics,and the tensile properties are constructed,which provide guidelines for developing high strength and toughness Al–Mg–Si–Ti alloys for high-pressure die-casting.展开更多
文摘The effect of W on the microstructure and the mechanical properties of ultrahigh strength low alloy steels was carried out. The microstructure of 30Cr3Si2Mn2NiMoNb and 30Cr3Si2Mn2NiMoNbW steels under quenched conditions were investigated by metallographic microscope, scanning electron microscope （SEM）, X-ray diffrac- tion （XRD）, and transmission electron microscope （TEM）. Thermodynamic cal- culation was also conducted. The results showed that the addition of W made undissolved carbides more and finer, which exerted strong pinning force on migrat- ing packet boundary and improved tensile strength significantly. M6C particles in 30Cr3Si2Mn2NiMoNb steel were disappeared above 1193 K, while the M6C particles in 30Cr3Si2Mn2NiMoNbW steel were disappeared above 1253 K, the calculation results were in agreement with the experimental.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301001)the Science&Technology Program of Zhaoqing(No.2018K006)。
文摘Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg-y Si-z Ti alloys have been investigated.The analysis of variance shows that both Mg and Si apparently infl uence the tensile properties of the alloys,while Ti does not.The tensile mechanical properties are comprehensively infl uenced by the amount of eutectic phase(α-Al+Mg2Si),the average grain size,and the content of Mg dissolved intoα-Al matrix.The optimized alloy is Al-7.49 Mg-3.08 Si-0.01 Ti(wt%),which exhibits tensile yield strength of 219 MPa,ultimate tensile strength of 401 MPa,and elongation of 10.5%.Furthermore,contour maps,showing the relationship among compositions,microstructure characteristics,and the tensile properties are constructed,which provide guidelines for developing high strength and toughness Al–Mg–Si–Ti alloys for high-pressure die-casting.
