Low Cr Contents Research Articles

Behavior of high-strength stainless steel S600E welded I-section beams

S600E is a new type of high-strength stainless steel with sorbite microstructure. Its yield strength is as high as 600 MPa, and its cost is lower than the commonly used stainless steel due to its low content of precious metallic elements Ni and Cr. This paper studied the bending capacity of high-strength stainless steel S600E welded I-section beams with lateral-torsional buckling. Tests on seven I-section beams were performed using an innovative four-point bending test rig. Thereafter, comparisons between the bending capacities and the values predicted using the current Eurocode, American code, and Chinese specification were conducted. The results showed that the predictions of the three existing codes were all conservative. Finite element models for the beams were established and verified, meanwhile, parametric analyses based on the simplified models were carried out on the influence of key parameters. Subsequently, through the results of the test and finite element analysis, the design formula for the lateral-torsional buckling was modified and the design formula for the local buckling in the companion study was verified. The complete design procedure of high-strength stainless steel S600E I-section beams was developed by the combination of the two formulae. Finally, to prove the accuracy of the design method proposed in this paper, comparisons between the predictions of the proposed method with the test data and four hundred finite element models were conducted.

The effect of Mn addition on corrosion behaviour of equiatomic CoCrFeNi high entropy alloys in NaCl solution

ABSTRACT The corrosion behaviour of equiatomic CoCrFeNi and CoCrFeNiMn high entropy alloys manufactured by the vacuum arc melting were studied in 3.5 wt-% NaCl solution. And the reasons for the differences in corrosion resistance were investigated in terms of microstructure, electrochemical behaviour and oxide film. The results show that the two alloys exhibit different corrosion characteristics, with CoCrFeNi alloy displaying typical passivation characteristics and CoCrFeNiMn alloy exhibiting activation behaviour. The CoCrFeNi HEA with compact and protective passive film has lower corrosion current density, larger film resistance and polarisation resistance, meaning a lower corrosion rate and superior corrosion resistance compared with those of CoCrFeNiMn alloy. Moreover, CoCrFeNiMn alloy forms a discontinuous and loose corrosion product film with higher Mn content and lower contents of Cr, Fe and Co compared to the matrix, which decreases its protection performance. The addition of Mn changes the electrochemical behaviour, and higher Mn oxides/hydroxides within oxide film are unfavourable to forming a stable passive film.

Pressure effect on the structural, magnetic and thermophysical properties of X12Cr13 martensitic stainless steel prepared by powder metallurgy method

Low carbon (C: 0.03-0.15%) and high Cr contents (Cr: 11-15%) martensitic stainless steel (MSS) is widely used for industrial applications due to its good mechanical properties and corrosion resistance. In this study, we investigated the pressure effect on the structural, magnetic and thermophysical properties of X12Cr13 MSS which was compacted using powder metallurgy method under 400 and 600 MPa pressures and sintered at 1200 °C temperature for an hour under Ar atmosphere. Pressing and sintering processes resulted in increased density of microstructures from 5.84 g/cm 3 to 6.12 g/cm 3 , decreased porosity from 7.58% to 3.39%, increased hardness from 93.24 HB to 110.09 HB (N/ mm 2 ) and decreased carbide particles from 2.65% to 2.13 wt% in the structures. We observed α -Fe, γ -Fe and M 23 C 6 (M: Cr or Fe) phase formations in the structure due to the applied pressure and the sintering process. The magnetic properties of these steels have been investigated as a function of temperature between 300-400 K and applied magnetic field of ±4 T. We observed improved magnetic properties with increasing pressure, and ferromagnetic to paramagnetic phase transition occurred from 300 K to 400 K. While maximum saturation magnetization is found to be 70 emu/g at 300 K for 600 MPa sample, maximum magnetic susceptibility and permeability for 600 MPa sintered sample are recorded as 17.13 and 1.08 m 3 /kg, respectively. Also, the maximum specific heat capacity and enthalpy are recorded as 1.85 J/g °C and 536.05 J/g (at 579 °C temperature) on the sample compacted on the 600 MPa pressure, respectively. • X12Cr13 MSS samples were prepared by P/M method at 400 MPa and 600 MPa. • 600 MPa pressing and 1200 °C sintering enhanced physical and magnetic properties • MSS prepared at 600 MPa exhibits 110.09 HB hardness and 6.12 g/cm 3 density. • The maximum saturation magnetization found to be 70 emu/g at RT for 600 MPa sample. • The 600 MPa sample provided 536.0 J/g heat storage capacity at 579°C.

A transverse Ising model for the Fe50-xCr25+xV25 Heusler alloy

• Cr contents are modelled by EFT. • M-T curves are obtained. • TIM is very successful for the lower Cr contents. • Critical transverse fields are obtained vs Cr contents. Effects of chromium (Cr) contents on ferromagnetic properties of the Heusler alloy are modeled and analyzed by using the effective field theory (EFT) in the context of the transverse Ising model (TIM). Temperature dependent results due to variations in magnetization and Curie temperature are provided. The bridge constant between EFT and experimental magnetization is obtained as k=140. It is shown that the theoretical results of magnetization match with the experimental results reported by Shen et al. for a certain critical transverse field. Cr content effects on the transverse field.

Effect of Cr on Isothermal Structure Transformation of Iron Oxide Scale

Herein, the effect of different contents of Cr on the isothermal structure transformation of FeO is systematically studied by a thermogravimetric analyzer, and it is found that the temperature range of eutectoid transformation of FeO in Fe–Cr alloy is 300–500 °C. Combined with the experimental data, the kinetic model of isothermal phase transformation of FeO is established based on Johnson–Mehl–Avrami–Kolmogorov equation, and the time–temperature–transformation curve of isothermal transformation of FeO is predicted, which follows the law of C curve, and the C curve shifts backward with the increase of Cr content. Therm‐calc thermodynamic software calculates the Fe–O phase diagrams of different Cr contents. Combined with the experimental results, the effect mechanism of Cr content on FeO eutectoid transformation is clarified. With the increase of Cr content, the stability of FeO decreases, and under the same isothermal temperature and time, high Cr content has greater undercooling, a higher driving force of phase transition, and the starting time of eutectoid transformation is earlier than that of lower Cr content.

Petrogenesis of Jian forsterite jade solely composed of end-member forsterite (Fo 99.8): Constrained by trace element and oxygen isotope

The Jian forsterite jade, named for its enrichment of end-member forsterite, is a new type of jade discovered in Ji'an County (Jilin Province, Northeast China). The formation mechanism of this rare end-member forsterite remains unclear. In this study, we present the mineral chemistry and oxygen isotope analysis of end-member forsterite to elucidate the formation mechanism of the Jian forsterite jade. The Jian forsterite jade can be divided into three main types: yellowish-green, dark-green, and black. The Jian forsterite jade consists mainly of forsterite, serpentine, as well as minor brucite, spinel, phlogopite, dolomite, calcite, magnesite, and magnetite. The Fo% content (100 × Mg/[Mg + Fe], mol%) of forsterite varies from 96.69 to 99.82. All tested forsterite samples show low Ni, Mn, Cr, and Ca contents and very high B contents. The δ18O values of forsterite range from 13.79 ‰ to 18.57 ‰, which are significantly higher than those from the mantle and are similar to those from skarn, marble, and calc-silicate rocks. The oxygen isotope values of forsterite, coupled with a distinctive trace element signature, suggest that the genesis of end-member forsterite results from a siliceous fluid-mediated decarbonation of Mg-rich dolomite. The genesis of the Jian forsterite jade can be outlined in two main metamorphic stages: (1) high-temperature prograde stage related to the interaction of the gneiss-derived SiO2-rich fluids with overlying dolomite. High temperature leads to the formation of forsterite, spinel, and calcite mineral assemblage. (2) low-temperature retrograde stage characterized by the infiltration of hydrous fluids. Hydrous silicate minerals, mostly serpentine, phlogopite, and talc, are formed during this stage. Our work highlights and confirms the effectiveness of the trace element geochemistry of forsterite in identifying magnesian skarns, and classifies the forsterite in the Jian forsterite jade as an extreme example of this occurrence.

Bio-Geochemical Processes: Insights from Fe-Mn Mineralization in the Aegean Sea (Greece)

In this study, we have compiled new and existing mineralogical and geochemical data on Fe-Mn mineralization from the Aegean region [Attica (Grammatiko, Legrena, and Varnavas), Evia and Milos islands], aiming to provide new insights on the genesis of Fe-Mn mineralization in that region and its potential environmental implications. A common feature of those deposits is the relatively low Cr, Co, V, Ni, Mo, and Cd content, whereas Ba, As, W, Cu, Pb, and Zn show remarkably variable values. The Mn-Fe deposits from Milos exhibit the highest tungsten content, while a positive trend between MnO and W, combined with a negative trend between MnO and Fe2O3 suggests the preference of W to Mn-minerals. The occurrence of bacterio-morphic Fe-Mn-oxides/hydroxides within Mn-Fe mineralizations in the studied region, indicates the important role of micro-organisms into redox reactions. Moreover, the presence of micro-organisms in the Fe-Mn-deposits, reflecting the presence of organic matter confirms a shallow marine environment for their deposition. A salient feature of the Varnavas and Milos Mn-Fe ores is the presence of sodium chloride coated fossilized micro-organisms, suggesting development from a solution containing relatively high Na and Cl concentrations. Furthermore, from an environmental point of view, consideration is given to the bioavailability of elements such as As, Pb, and W, related to the above-mentioned mineralizations. The high bio-accumulation factor for W (Wplant/Wsoil × 100) recorded in the Neogene sedimentary basins of Attica, related to the Grammatiko Fe-Mn mineralization, reflects the high W mobility under alkaline conditions and the potential environmental impact of similar deposits with elevated W content.

Nano-eutectic structure induced oxide layer improving the wear resistance of CoCrxNiMoCB laser-clad coating

CoCrxNiMoCB coatings with different contents of Cr were prepared by laser cladding. While the microhardness was increased with the increased addition of Cr, the wear resistance exhibited a decreasing trend. Based on the wear tracks analysis, it was concluded that the oxide layers formed on the surface of the wear tracks with low Cr content coatings were the reason for their the low wear volume losses. The nano-eutectic structure was proved to be beneficial for the formation of the oxide layer that adhered to the wear track surfaces.

Effect of Carboxylic Acids on Corrosion of Type 410 Stainless Steel in Pyrolysis Bio-Oil

Biomass-derived oils are renewable fuel sources and commodity products and are proposed to partially or entirely replace fossil fuels in sectors generally considered difficult to decarbonize such as aviation and maritime propulsion. Bio-oils contain a range of organic compounds with varying functional groups which can lead to polarity-driven phase separation and corrosion of containment materials during processing and storage. Polar compounds, such as organic acids and other oxygenates, are abundant in bio-oils and are considered corrosive to structural alloys, particularly to those with a low-Cr content. To study the corrosion effects of small carboxylic acids present in pyrolysis bio-oils, type 410 stainless steel (SS410) specimens were exposed in bio-oils with varying formic, acetic, propionic and hexanoic acid contents at 50 °C during 48 h exposures. The specific mass change data show a linear increase in mass loss with increasing formic acid concentration. Interestingly, a mild corrosion inhibition effect on the corrosion of SS410 specimens was observed with the addition of acetic, propionic and hexanoic acids in the bio-oil.

Stress corrosion cracking of AISI 304 under chromium variation within the standard limits: Failure analysis implementing microcapillary method

This study focuses on the failure analysis of an industrial part made of AISI 304 that severely ruptured, while another identical part operated under identical service conditions has no sign of fracture. Various electrochemical polarization responses and stress corrosion cracking (SCC) susceptibility were compared by employing the microcapillary method on representative samples. The dominant factor was identified to be the chromium (Cr) content variation within the range of standard designations. Various concentration levels of sodium chloride aqueous solution were studied for both strained and unstrained conditions. Results highlighted higher susceptibility to pitting and SCC for the specimens with lower Cr content, indicating a more severe condition at higher chloride concentrations.

Petrogenesis of newly identified Neoarchean granitoids in the Qingyuan of NE China: Implications on crustal growth and reworking of the North China Craton

• A new ca. 2.7–2.5 Ga granitoid suite was identified in the Qingyuan, NE China. • The 2.68 Ga TTG was derived from ancient lower crust as well as juvenile crust. • Qingyuan granitoids record two periods of crustal growth and reworking events. Discovery of ca. 2.7 Ga tonalite-trondhjemite-granodiorite (TTG) in the North China Craton (NCC) can provide the key clue to understanding the Neoarchean crustal evolution. Most recently, we mapped out ca. 2.7 Ga TTGs from the northern Qingyuan at the northeastern margin of NCC. Together with the associated ca. 2.6–2.5 Ga high-K granites and high-Mg diorites, this study provides new constraints on crustal growth and reworking during the Neoarchean. Zircon U–Pb dating indicates that the TTGs, high-K granites and high-Mg diorites were formed at ca. 2.68 Ga, ca. 2.56 Ga and ca. 2.54 Ga, respectively. All of these lithologies exhibit enrichments in large ion lithophile elements (e.g., Rb and Ba) but depletions in high field strength elements (e.g., Nb and Ta), with positive εHf(t) and εNd(t) values. The TTGs have moderate SiO 2 , low Al 2 O 3 and variable MgO contents with high Sr/Y and (La/Yb) N ratios. They were likely derived from partial melting of mafic lower crust. High SiO 2 and K 2 O but low MgO and Cr contents as well as high Sr/Y and (La/Yb) N ratios reflect an origin of recycling of ancient crustal rocks (e.g., pre-existing TTGs) for the high-K granites. The high-Mg diorites have high MgO and Cr contents but low Sr/Y and (La/Yb) N ratios, which indicate that they could be sourced from partial melting of metasomatized mantle peridotite. Combined with previous studies, the northeastern NCC experienced two major periods of ca. 2.7 Ga and ca. 2.6–2.5 Ga crustal growth and reworking events.

Tailoring the composition of the functional Cu–Cr–Zr–La/Ce alloys for electromechanical applications

Tailoring the compositions of the functional Cu–Cr–Zr–La/Ce alloys involve producing alloys with dilute (0.05%), low (0.16–0.2%), medium (0.41–0.44%), and high (0.66–0.91%) Cr content at dilute (0.06%), medium (0.5%), and high (0.98%) Zr content with (0.23–0.4%) La or (0.03–0.12%) Ce. The effect of these compositional differences on the microstructure, hardness, and electrical properties was studied for different aging times (0, 1, and 1.5 h). The best combination of hardness and electrical properties was achieved after 1.5 h of aging for all studied alloys. The effect of the chemical composition on tensile properties and wear resistance was studied after 1.5 h of aging. Unlike Zr, high Cr content has a negative influence on the tensile strength and wear resistance.

Influence of Cold-Rolling Reduction on Microstructure and Tensile Properties of Nuclear FeCrAl Alloy with Low Cr and Nb Contents

Influence of Cold-Rolling Reduction on Microstructure and Tensile Properties of Nuclear FeCrAl Alloy with Low Cr and Nb Contents

Combined Treatment of Cr(VI)-Contaminated Soils by Reduction, Adsorption, and Solidification

Remediation of Cr(VI)-contaminated soil usually includes reducing Cr(VI) to Cr(III) with sub-sequent solidification. In this paper, a treatment technique that combines reduction, adsorption, and solidification was proposed. By introducing an adsorbent into the reduction process, the remediation effectiveness was improved and the amount of reducing and solidified agent was decreased. Synthetic precipitation leaching procedure (SPLP), unconfined compressive strength (UCS) test, and scanning electron microscope (SEM) analysis were carried out to evaluate the remediation effect under different agent combinations and different agent-adding procedures. The results of SPLP showed that the reduction/adsorption/solidification treatment significantly reduced the leachability of Cr. UCS increased with increasing dosage of cement and CaS5, and decreased with an increasing dosage of vermiculite. The best agent dosage was CaS5 of 2 times molar stoichiometric ratio of Cr(VI), 15% of vermiculite, and 20% of cement. Orthogonal test showed that for soil with low Cr(VI) content, CaS5 dosage was the most important factor that affected the leachability of Cr. Cement and vermiculite have greater impact in limiting the leachability of Cr when Cr(VI) content in soil increased.

From conventional to inverse magnetocaloric effect in GdMn1-x Cr x O3

In this work, a phenomenological model (PM) is used to simulate the magnetocaloric effect (MCE) of GdMn1-x Cr x O3 (0 ≤x ≤0.4) (GMCO) samples through the modelling of experimental isofield thermo-magnetization curves. The results showed that the MCE of GMCO samples depends strongly on Cr content, achieving a conventional MCE for low Cr content (level of doping x ≤ 0.3). However, the MCE of a higher Cr content sample has an inverse MCE. The behaviour of MCE in GMCO samples indicated that GMCO compounds are interesting magnetocaloric materials and can fruitfully be functioned as cryogenic magnetic refrigerants below 40 K especially in radiation detectors for outer space research.

Study on the relation between the crystal structure and thermal stability of FeUO4 and CrUO4

FeUO4, CrUO4, and FexCr1-xUO4 are monouranates containing pentavalent U. Despite having similar crystal structures, the formation conditions and thermal stability of these compounds are significantly different. To determine the factors causing the thermal stability differences between FeUO4 and CrUO4, their crystal structures were evaluated in detail. A Raman band was observed at 700 cm−1 in all samples. This Raman band was derived from the stretching vibration of the O–U–O (‘uranyl’) axis band, indicating that FexCr1-xUO4 was composed of a uranyl-like structure in its lattice regardless of its “x” value. Mössbauer measurements indicated that the Fe in FeUO4 and FexCr1-xUO4 were trivalent. Furthermore, FexCr1-xUO4 lost its symmetry around FeIII with increasing electron densities around FeIII as the abundance of Cr increased. These results suggest no significant structural differences between FeUO4 and CrUO4. Thermogravimetric measurements for UO2, FeUO4, and CrUO4 showed that the temperature at which FeUO4 decomposed under an oxidizing condition (approximately 1073 K) was significantly lower than the temperature at which CrUO4 decomposition started (approximately 1523 K). Based on these results, we concluded that FeUO4 decomposition was triggered by an “in-crystal” redox reaction, i.e., FeIII + UV → FeII + UVI, which would not occur in the CrUO4 lattice because CrIII could never be reduced under the investigated condition. Finally, the existence of CrIII in FexCr1-xUO4 effectively suppressed FexCr1-xUO4 crystal decomposition, even at a very low Cr content.

Petrogenesis and tectonic implications of 1.86–1.80 Ga A-type granites in the Daqingshan Complex, Khondalite Belt, North China Craton

The Khondalite Belt is regarded as a Paleoproterozoic continent–continent collisional belt along which the Yinshan Block and the Ordos Block amalgamated to form the Western Block in the North China Craton. Associated with the collision of the Yinshan and Ordos Blocks was granitic magmatism represented by quartz monzogranites in the Khondalite Belt, whose petrology, geochemistry and petrogenesis will provide important insights into understanding of the crustal evolution of the Khondalite Belt in the late Paleoproterozoic. In this paper, we carried out a detailed study on the petrography, geochronology, whole-rock geochemistry, and zircon Lu-Hf isotope of quartz monzogranites exposed in the Daqingshan Complex of the Khondalite Belt. Zircon LA-ICP-MS U-Pb dating results show that the Daqingshan quartz monzogranites were formed at 1.86–1.80 Ga, at some time posterior to the ∼ 1.95 Ga collision of the Yinshan and Ordos Blocks. Geochemically, the Daqingshan quartz monzogranites belong to ferroan, metaluminous to peraluminous, calc-alkalic to alkalic-calc series, exhibiting high SiO2, Na2O, K2O and FeOT / (FeOT + MgO), low Al2O3, MgO and CaO, and high Zr, Nb, Ce and Y, low Cr and Ni contents, with an affinity of A-type granites. In terms of REE and trace elements, the Daqingshan quartz monzogranites have right dipping patterns and negative Eu anomalies, enriched large ion lithophile elements (LILEs) (e.g. Rb, Zr and Hf), and depleted high field strength elements (HFSEs) (e.g. Ta, P and Ti). Zircon Lu-Hf isotopic characteristics (εHf(t) = -9.63 – −4.31, TDMC = 2744–3050 Ma) indicate that the Daqingshan quartz monzogranites were most likely originated from the partial melting of a Neoarchean ancient crust. Combining new results presented in this paper with previous data, we propose that the quartz monzogranites in the Daqingshan Complex were derived from the partial melting of Neoarchean TTG rocks under high temperatures caused by the upwelling of mantle magmas under a post-collision extensional setting. Meanwhile, it indicates that the Khondalite Belt completed collision at 1.86–1.80 Ga to form the Western Block.

Mid-Neoproterozoic magmatism in the South Qilian Belt, NE Tibetan Plateau and its tectonic implications

AbstractWidely distributed Mid-Neoproterozoic mafic rocks of the Qilian – Qaidam – East Kunlun region record the tectonic evolution of the northeastern Tibetan Plateau. This study presents whole-rock geochemistry, zircon U–Pb geochronology and Hf isotopes for the Xialanuoer gabbros of the central South Qilian Belt (SQB). Zircon laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) U–Pb dating indicates that the gabbros were emplaced at ca. 738 Ma, indicating they are contemporaneous with mafic magmatism elsewhere in the northeastern Tibetan Plateau. The gabbros have low SiO2, Cr and Ni contents and Mg# values, are relatively enriched in light rare-earth elements (LREEs) and depleted in high-field-strength elements (HFSEs; e.g. Nb and Ta), have no positive Zr or Hf anomalies and have relatively high Nb/Ta but low Nb/La ratios. These data indicate that the Xialanuoer gabbros formed from calc-alkaline basaltic magmas that were originally generated by the partial melting of an enriched mantle of type-I (EMI-type) enriched region of the lithospheric mantle, underwent little to no crustal contamination prior to their emplacement, and have within-plate basalt geochemical affinities. Combining these data with the presence of widespread contemporaneous continental rift-related magmatism and sedimentation in the North Qilian, Central Qilian, South Qilian, Quanji, North Qaidam and East Kunlun regions suggests that the northeastern Tibetan Plateau underwent Mid-Neoproterozoic continental rifting, which also affected other Rodinian blocks (e.g. Tarim, South China, Australia, North America and Southern Africa).

Speciation and Bio-Imaging of Chromium in Taraxacum officinale Using HPLC Post-column ID-ICP-MS, High Resolution MS and Laser Ablation ICP-MS Techniques.

A new analytical procedure for the speciation of chromium (Cr) in plants by high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was developed using a strong anion-exchange Mono Q column for the separation of the Cr species. To optimize the analytical procedure, Cr complexes were first synthesized from Cr-nitrate with the addition of an excess of ligand (90°C). Cr-oxalate, Cr-malate, Cr-citrate, Cr-aconitate and Cr-quinate complexes and Cr-nitrate (pH 6.5) were chromatographically separated from Cr(VI) by applying linear gradient elution from 100% water to 100% NH4Cl at a flow rate of 1.5 ml min−1 in 10 min. The column recoveries ranged from 100 to 104%. The exception was Cr-aconitate (column recovery 33%), where a quantitative synthesis was not possible. Good repeatability of the measurements (relative standard deviations better than ± 3%) and low limits of detection (below 0.37 ng ml−1 Cr) were achieved for the individual Cr species. The developed analytical procedure was applied to Cr speciation for dandelions (Taraxacum officinale) grown in soil with a high Cr content and a study of the uptake and metabolism of Cr species in dandelions grown in soil with a low Cr content treated with solutions of Cr(VI) or Cr-nitrate (5000 ng ml−1 Cr, pH 6.5) for 48 h. The separated Cr species were quantified by post-column isotope dilution ICP-MS, while the identification was based on retention times and was also supported by mass spectra obtained with high resolution mass spectrometry (HR-MS). The data indicate that for dandelions grown in Cr-rich soil and that treated with Cr-nitrate (pH 6.5), the Cr was mainly accumulated in the roots, while in plants treated with Cr(VI) (pH 6.5), the Cr was evenly distributed between the roots and the leaves. The Cr species found in dandelion roots and leaves were Cr-aconitate, Cr-malate, and Cr-quinate. The results revealed that Cr(VI) was completely reduced and metabolized to Cr(III) complexes. LA-ICP-MS data showed that the Cr in a leaf of dandelion grown in Cr-rich soil was localized mainly at the apex of the leaf.

Connected volcanic and plutonic association by crystal-melt segregation in the Daiyunshan volcanic field, SE China

The Daiyunshan volcanic field is one of the largest volcanic fields in the volcanic-plutonic complex belt along the coast of SE China, which records a long volcanic activity history from the Late Jurassic to the Late Cretaceous. In this paper, we conduct comprehensive petrological, geochemical, isotopic and zircon trace element analyses for two representative calderas (Shiniushan and Yunshan) to reveal the crystal-melt segregation and magma recharge processes of the Daiyunshan volcanic field. Systematic LA-ICP-MS zircon U-Pb dating and isotope analyses reveal that the porphyritic quartz monzonite, porphyritic granite and rhyolite of the Shiniushan caldera have identical crystallization ages (97–94 Ma) and consistent Nd-Hf isotope compositions [εNd(t) = −3.6 to −2.8; zircon εHf(t) = −2.7 to 1.8], which are consistent with those of the porphyritic quartz monzonite and rhyolites in the nearby Yunshan caldera, indicating that the magmas of the two calderas were derived from a common magma source region. Volcanic-plutonic rocks from two calderas display metaluminous to peraluminous features and have low MgO, FeOT, Ni and Cr contents. We thus suggest that their parental magmas were derived by remelting of pre-existing crust with contributions of juvenile components. The Shiniushan porphyritic granite and rhyolite and the Yunshan rhyolites are characterized by distinctly negative Eu anomalies and depletions of Ba, Sr, P and Ti, while the porphyritic quartz monzonites from both calderas show complementary geochemical signatures, such as positive Ba anomalies and neglectable Eu anomalies. The back-scattered electron (BSE) images and energy-dispersive X-ray spectrometry (EDS) phase mapping of the Shiniushan porphyritic quartz monzonite reveal textural indicators of crystal accumulation, such as imbrication and synneusis of plagioclase phenocrysts. Their interstitial assemblages of K-feldspar, quartz and plagioclase commonly resemble the phenocryst assemblages of porphyritic granite. We believe that the Shiniushan porphyritic granite and rhyolite and Yunshan rhyolites represent extracted melts from the mush reservoir, while porphyritic quartz monzonites in both calderas are inherent cumulates that have lost interstitial melts. Therefore, our study shows that the Late Cretaceous volcanic-plutonic rocks in the Daiyunshan volcanic field should be connected by crystal-melt segregation processes. Furthermore, a typical zigzag variation in zircon εHf(t) values is shown by the Late Jurassic to Late Cretaceous volcanic-plutonic rocks from the Daiyunshan volcanic field, indicating variable contributions of asthenospheric mantle-derived melts and the multistage slab rollback of the subducting paleo-Pacific plate beneath SE China.