期刊文献+
共找到2,135篇文章
< 1 2 107 >
每页显示 20 50 100
CYCLIC SOFTENING IN HOT-WORKING DIE STEELS DURING LOW-CYCLE FATIGUE 被引量:1
1
作者 HU Zhenhua XIAO Jiexuan Huazhong University of Science and Technology,Wuhan,China HU Zhenhua,Associate Professor,Huazhong University of Science and Technology,Wuhan 430074,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1990年第3期199-203,共5页
The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle fatigue.The re- sults show that the cyclic softening... The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle fatigue.The re- sults show that the cyclic softening is featured in both steels hardened in different conditions under the strain controlled amplitude range of Δε_t/2=0.6-1.8×10^(-2).The softening effect mainly occurs in some initial cycles and the stress amplitude varies slightly in the sequential cycles,i.e.the softening effect is minified.No obvious stress saturation phenomenon was ob- served during the whole cyclic deformation.The TEM analysis shows that the cyclic softening is related to heterogenity of plastic deformation.The softening of the tested steels is caused by the formation of the dislocation cell structure with low density and low internal stress,and by the fragmentation and redissolution of fine carbides into matrix. 展开更多
关键词 low-cycle fatigue hot work die steel cyclic softening
下载PDF
APPLICATION OF RARE EARTH IN SURFACE HEAT TREATMENT OF HOT-WORKING DIE STEELS 被引量:1
2
作者 胡正前 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1997年第Z1期138-145,共8页
This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused laye... This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused layer. XRD and SEM energy spectrum prove that trace RE element actually penetrates into the surface layer of steels. The result shows that RE can reduce the gradient of change of hardness in diffused layer, improve the morphology and distribution of compounds , and reduce the degree of surface alligator crack for thermal fatigue. The behavior of thermal fatigue of hot-working die steels is raised by 70% or so after the application of RE. The effect of RE is analysed according to the theory. 展开更多
关键词 rare earth chemical heat treatment hot -working die steel behavior of thermal fatigue.
下载PDF
Effect of Rare Earth Composite Modification on Microstructure and Properties of a New Cast Hot-Work Die Steel 被引量:3
3
作者 关庆丰 方建儒 +1 位作者 姜启川 王树奇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第3期368-371,共4页
The effects of RE modification on structure and the properties of a new cast hot work die (CHD) steel were investigated. The grains of the CHD steel are refined by RE modification. With the increase of RE addition, b... The effects of RE modification on structure and the properties of a new cast hot work die (CHD) steel were investigated. The grains of the CHD steel are refined by RE modification. With the increase of RE addition, both grain size and inclusion amount are reduced. Appropriate amount of RE results in decrease in inclusion amount and formation of spheroidal inclusions uniformly-distributed in steel, so that the morphology and distribution of inclusions are improved. RE composite modification favors the formation of bainite, austenite and fine lath martensite with dense dislocation. When the residual RE content reaches 0.02%, no obvious changes in strength and hardness are found, while fracture toughness and threshold of fatigue crack growth are increased. The impact toughness, elongation and reduction of cross sectional area are increased by a factor of two, and thermal fatigue resistance is also improved. 展开更多
关键词 metal materials modification cast hot work die steel thermal fatigue rare earths
下载PDF
Development and application of a new hot-work die steel for hot stamping 被引量:7
4
作者 GUAN Hong LUO Aihui 《Baosteel Technical Research》 CAS 2017年第2期11-17,共7页
A new hot-work die steel for hot stamping was developed, and used the die for mass production. The produced die showed good performance owing to its high heat conductivity and wear-resistant characteristics. Two diffe... A new hot-work die steel for hot stamping was developed, and used the die for mass production. The produced die showed good performance owing to its high heat conductivity and wear-resistant characteristics. Two different benchmarking hot-work die steels were investigated, and then compared in terms of their impact ductility, temper characteristics ,heat conductivity, and thermal stability. The result of the high-temperature friction wear test indicated that oxidative wear was the main mode in high temperature. On the basis of the comparison and test results, the alloying composition of the new hot-work die steel was especially designed. The new die steel showed good performance with good wear-resistant quality, as well as temper hardness and heat conductivity of HRC 50 and 34.3 W/( m ~ K), respectively. Furthermore, without surface plasma nitriding, the die made of the new steel had no obvious galling with 6 142 strokes. After surface plasma nitriding, the die completed 40 000 strokes with good surface. The die life is expected to exceed 200 000 strokes. 展开更多
关键词 hot-work steel temper resistance thermal conductivity high temperature wear resistance plasma nitriding
下载PDF
Study on Key Joining Technology and Test Method of Steel/Al Hybrid Structure Body-in-White
5
作者 Lijun Han Fuyang Liu Changhua Liu 《Journal of Materials Science and Chemical Engineering》 2024年第4期104-118,共15页
Green and low carbon promote the application and development of light-weight materials in body-in-white. Large-scale die-casting Al alloy (DCAA) and high-strength thermo-formed steel sheet (TFSS) have put forward high... Green and low carbon promote the application and development of light-weight materials in body-in-white. Large-scale die-casting Al alloy (DCAA) and high-strength thermo-formed steel sheet (TFSS) have put forward higher requirements for the application of joining technology of high-strength steel/Al dissimilar materials. Taking the new die-casting Al alloy body as an example, this paper systematically studies the progress of the latest joining methods of steel/Al dissimilar material with combination of two-layer plate and three-layer plate. By analyzing the joining technologies such as FSPR, RES, FDS and SPR, the technology and process characteristics of steel/Al dissimilar material joining are studied, and the joining technical feasibility and realization means of different material combination of the body are analyzed. The conditions of material combination, material thickness, material strength, flange height, preformed holes and joint spacing for achieving high-quality joining are given. The FSPR joining technology is developed and tested in order to meet with the joining of parts with DCAA and TFSS, especially for the joining of three-layer plates with them. It finds the method and technical basis for the realization of high quality joining of dissimilar materials, provides the early conditions for the application of large DCAA and TFSS parts in body-in-white, and meets the design requirements of new energy body. . 展开更多
关键词 BODY-IN-WHITE LIGHTWEIGHT die-Casting Al Alloy Thermo-Formed steel Joining
下载PDF
Effects of heat treatment on the microstructures and mechanical properties of a new type of nitrogen-containing die steel 被引量:7
6
作者 Jing-yuan Li Peng Zhao +2 位作者 Jun Yanagimoto Sumio Sugiyama Yu-lai Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第6期511-517,共7页
Nitrogen can increase the strength of steels without weakening the toughness and improve the corrosion resistance at the same time. Compared with conventional nitrogen-free die steels, a new type of nitrogen-containin... Nitrogen can increase the strength of steels without weakening the toughness and improve the corrosion resistance at the same time. Compared with conventional nitrogen-free die steels, a new type of nitrogen-containing die steel was developed with many superior properties, such as high strength, high hardness, and good toughness. This paper focused on the effects of heat treatment on the microstruc- tures and mechanical properties of the new type of nitrogen-containing die steel, which were investigated by the optimized deformation process and heat treatment. Isothermal spheroidal annealing and high-temperature quenching as well as high-temperature tempering were ap- plied in the experiment by means of an orthogonal method after the steel was multiply forged. The mechanical properties of nitro- gen-containing die steel forgings are better than the standard of NADCA #207-2003. 展开更多
关键词 die steels NITROGEN heat treatment microstructure mechanical properties forgings
下载PDF
Effect of Alloying Elements on Thermal Wear of Cast Hot-Forging Die Steels 被引量:8
7
作者 WANG Shu-qi CHEN Kang-min +2 位作者 CUI Xiang-hong JIANG Qi-chuan HONG Bian 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第5期53-59,共7页
The effect of main alloying elements on thermal wear of cast hot-forging die steels was studied. The wear mechanism was discussed. The results show that alloying elements have significant influences on the thermal wea... The effect of main alloying elements on thermal wear of cast hot-forging die steels was studied. The wear mechanism was discussed. The results show that alloying elements have significant influences on the thermal wear of cast hot-forging die steels. The wear rates decrease with an increase in chromium content from 3% to 4% and molybdenum content from 2% to 3%, respectively. With further increase of chromium and molybdenum contents, chromium slightly reduces the wear resistance and molybdenum severely deteriorates the wear resistance with high wear rate. Lower vanadium/carbon ratio (1.5-2.5) leads to a lower wear resistance with higher wear rate. With an increase in vanadium/carbon ratio, the wear resistance of the cast steel substantially increases. When vanadium/carbon ratio is 3, the wear rate reaches the lowest value. The predominant mechanism of thermal wear of cast hot-forging die steels are oxidation wear and fatigue delamination. The Fe2O3 and Fe3O4 or lumps of brittle wear debris are formed on the wear surface. 展开更多
关键词 hot-forging die cast steel alloying element thermal wear MECHANISM
下载PDF
Design of Quenching Process for Large-sized AISI P20 Steel Block Used as Plastic Die 被引量:7
8
作者 Dongli SONG Jianfeng GU Jiansheng PAN Xin YAO 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第1期139-144,共6页
For large-sized AISI P20 steel block used as plastic die with a thickness of more than 200 mm, appropriate quenching processes are the key to obtain much thick hardened layer. In this paper, different quenching proces... For large-sized AISI P20 steel block used as plastic die with a thickness of more than 200 mm, appropriate quenching processes are the key to obtain much thick hardened layer. In this paper, different quenching processes of AISI P20 steel block such as oil quenching, direct water quenching, water quenching with precooling and water quenching with pre-cooling and self-tempering were numerically investigated by computer simulation based on the detailed discussion on the mathematical models of quenching processes including partial differential equations of heat transfer, thermal physical properties, latent heat, heat transfer coefficient and calculation of phase transformation, The results show that the water quenching with pre-cooling and self-tempering process can not only effectively avoid quenching cracks, but also obtain deeper harden depth than oil quenching. 展开更多
关键词 Computer simulation Quenching process AISI P20 steel Plastic die
下载PDF
Research on Thermal Wear of Cast Hot Forging Die Steel Modified by Rare Earths 被引量:6
9
作者 崔向红 王树奇 +1 位作者 姜启川 陈康敏 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第1期88-92,共5页
Thermal wear of cast hot-forging die steel modified by rare earths(RE) was studied and compared with commercially used die steels. The function of RE and the mechanism of thermal wear of cast steel modified by RE we... Thermal wear of cast hot-forging die steel modified by rare earths(RE) was studied and compared with commercially used die steels. The function of RE and the mechanism of thermal wear of cast steel modified by RE were discussed. The results showed that with increasing content of RE, the wear rate of cast steel reduced at first and then increased. By adding 0.05% (mass fraction) RE, the cast hot-forging die steel with optimum thermal wear resistance was obtained, which was better than that of H13 and 3Cr2WSV. The large amount of coarse inclusions, (RE)2O2S, resulted from excessive RE, which obviously deteriorated thermal wear resistance. The mechanism of thermal wear of the modified cast die steel is oxidation wear and oxide fatigue delamination. The wear debris are lumps of Fe2O3 and Fe3O4. 展开更多
关键词 cast steel hot-forging die thermal wear rare earths
下载PDF
MECHANICAL STABILIZATION OF DEFORMED AUSTENITEDURING CONTINUOUS COOLING TRANSFORMATION IN AC-Mn-Cr-Ni-Mo PLASTIC DIE STEEL 被引量:7
10
作者 D.S.Liu G.D.Wang +1 位作者 X.H.Liu G.Z.Cui 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1998年第2期93-99,共7页
The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the pr... The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the prior deformation in low temperature region of austenite retards significantly the bainitic transformation. For the same continuous cooling schedule, as austenite deformed at lower temperature, the quantity of the classical sheaf-like bainite becomes less. The present results show that severe deformation leads to mechanical stabilization of austenite and causes the difficulty of bainitic ferrite propagation into the austenite. 展开更多
关键词 plastic die steel deformed austenite continuous cooling bainitic transformation mechanical stabilization of austenite
下载PDF
Tempering stability of Fe–Cr–Mo–W–V hot forging die steels 被引量:2
11
作者 Yuan-ji Shi Xiao-chun Wu +1 位作者 Jun-wan Li Na Min 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第10期1145-1157,共13页
The tempering stability of three Fe–Cr–Mo–W–V hot forging die steels(DM, H21, and H13) was investigated through hardness measurements and transmission electron microscopy(TEM) observations. Both dilatometer tests ... The tempering stability of three Fe–Cr–Mo–W–V hot forging die steels(DM, H21, and H13) was investigated through hardness measurements and transmission electron microscopy(TEM) observations. Both dilatometer tests and TEM observations revealed that DM steel has a higher tempering stability than H21 and H13 steels because of its substantial amount of M_2C(M represents metallic element) carbide precipitations. The activation energies of the M_2C carbide precipitation processes in DM, H21, and H13 steels are 236.4, 212.0, and 228.9 kJ/mol, respectively. Furthermore, the results indicated that vanadium atoms both increase the activation energy and affect the evolution of M_2C carbides, resulting in gradual dissolution rather than over-aging during tempering. 展开更多
关键词 TEMPERING stability hot FORGING die steelS CARBIDE PRECIPITATION
下载PDF
Calculation and Analysis of Valence Electron Structure of Mo_2C and V_4C_3 in Hot Working Die Steel 被引量:3
12
作者 LIU Yan LIU Zhi-lin ZHANG Cheng-weit 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第1期50-56,共7页
Taking the hot working die steel (HWDS) 4Cr3Mo2NbVNi as an example, the phase electron structures (PES) and the biphase interface electron structures (BIES) of Mo2C and V4 C3 , which are two kinds of important c... Taking the hot working die steel (HWDS) 4Cr3Mo2NbVNi as an example, the phase electron structures (PES) and the biphase interface electron structures (BIES) of Mo2C and V4 C3 , which are two kinds of important carbides precipitated during tempering in steel were calculated, on the basis of the empirical electron theory of solids and molecules and the improved TFD theory. The influence of Mo2 C and V4 C3 on the mechanical properties of HWDS has been analyzed at electron structure level, and the fundamental reason that the characteristic of the PES and the BIES of carbides decides the behavior of them has been revealed. 展开更多
关键词 phase structure factor interface conjunction factor hot working die steel CARBIDE
下载PDF
Effect of magnesium addition on inclusions in H13 die steel 被引量:6
13
作者 Zheng Wu Jing Li +1 位作者 Cheng-bin Shi Liang-liang Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第11期1062-1067,共6页
The effect of magnesium addition on the number, morphology, composition, size, and density of inclusions in H13 die steel was studied. The results show that the total oxygen content in the steel can be significantly d... The effect of magnesium addition on the number, morphology, composition, size, and density of inclusions in H13 die steel was studied. The results show that the total oxygen content in the steel can be significantly decreased to 0.0008wt%. Al2O3 and Mn S inclusions are changed into nearly spherical Mg O·Al2O3 spinel and spherical Mg O·Mg S inclusions, respectively. The number of inclusions larger than 1 μm decreases and the number of inclusions smaller than 1 μm increases with increasing magnesium content. V(N,C) precipitates around Mg O·Al2O3 and Mg O·Mg S inclusions during solidification of liquid steel. The densities of Mg O·Al2O3 spinel inclusions are lower than that of alumina inclusions. With increasing magnesium content in the Mg-containing inclusions, the density of inclusions decreases, leading to the improvement of inclusion removal efficiency. 展开更多
关键词 die steel inclusions magnesium deoxidation thermodynamics
下载PDF
Development of Flow Stress of AISI H13 Die Steel in Hard Machining 被引量:2
14
作者 闫洪 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2007年第2期187-190,共4页
An approach was presented to characterize the stress response of workpiece in hard machining, accounting for the effect of the initial workpiece hardness in addition to temperature, strain and strain rate on flow stre... An approach was presented to characterize the stress response of workpiece in hard machining, accounting for the effect of the initial workpiece hardness in addition to temperature, strain and strain rate on flow stress in this paper. AISI H13 die steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with experimental data. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response ofAISl H13 die steel with variation of the initial workpiece hardness in hard machining. 展开更多
关键词 flow stress hard machining finite element modeling AISI H13 die steel
下载PDF
Study on the microstructure and mechanical properties of medium carbon Cr-Si-Mn-Mo-V steel for cast inserted dies 被引量:1
15
作者 LIU Jin-hai LI Guo-lu +1 位作者 HAO Xiao-yan LIU Gen-sheng 《China Foundry》 SCIE CAS 2005年第4期260-263,共4页
The microstructure and mechanical properties of cast inserted dies for automobile covering components were studied. The results show that the as-cast microstructures of cast inserted dies are composed of pearlite, mar... The microstructure and mechanical properties of cast inserted dies for automobile covering components were studied. The results show that the as-cast microstructures of cast inserted dies are composed of pearlite, martensite, bainite, and austenite; and that the annealed microstructure is granular pearlite. The mechanical properties of cast inserted dies approach that of forged inserted dies. The tensile strength is 855 MPa, the elongation is 16%, the impact toughness is 177 J/cm2, and the hardness after annealing and quenching are HRC 19 and HRC 60-62. In addition, the cast inserted dies have good hardenability. The depth of the hardening zone and the hardness after flame quenching satisfy the operating requirements. The cast inserted dies could completely replace the forged inserted dies for making the dies of automobile covering components. 展开更多
关键词 steel CASTINGS inserted die microstructure mechanical properties FLAME QUENCHING
下载PDF
Effect of Si Content on Mechanical Properties of a Mo and V Free Low Alloy Cast Steel for Automobile Cold Pressing Die 被引量:1
16
作者 B.H.Kim J.S.Shin +4 位作者 S.M.Lee B.M.Moon H.D.Kim S.Y.Ju O.Y.Choi 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第3期313-316,共4页
The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low allo... The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing (SA), quenching and tempering (Q/T), and flame hardening (FH) treatments, respectively. The developed 0.8%-1.6%Si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert. 展开更多
关键词 Low alloy cast steel Cold pressing die die insert Matrix hardening Flame hardening
下载PDF
Computer Simulation of Carbide Transformation in Die Steel for Plastic 被引量:1
17
作者 HEYan-lin LILin PatrickWOLLANTS 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2005年第4期44-49,共6页
Thermo-Calc software package (TCP+DICTRA) was used to simulate the carbide transformation process in die steel for plastic. Combined with TEM analysis, the calculated result confirms that the carbide in equilibrium st... Thermo-Calc software package (TCP+DICTRA) was used to simulate the carbide transformation process in die steel for plastic. Combined with TEM analysis, the calculated result confirms that the carbide in equilibrium state is M_7C_3 carbide. The dissolution of M_7C_3 carbide in steel is predicted by DICTRA program. It was shown that the temperature remarkably affects the dissolution process of M_7C_3 carbide, but the influence of alloy elements such as manganese and molybdenum can be neglected in this steel. 展开更多
关键词 Thermo-Calc software package die steel for plastic M_7C_3 carbide TEM analysis
下载PDF
Fatigue Behavior of Cemented Carbide Die in Cold Forging of Steel 被引量:2
18
作者 Z.Wang and K.Dohda Dept. of Mechanical System Engineering, Gifu University, Gifu, Japan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第1期51-52,共2页
The fatigue behavior of cemented carbide die under service load in the multistage cold forging of steel was investigated. It was found that the fatigue cracks do not initiate at the stress concentration position and t... The fatigue behavior of cemented carbide die under service load in the multistage cold forging of steel was investigated. It was found that the fatigue cracks do not initiate at the stress concentration position and the crack initiation position can be classified to three types. The crack initiation position can be predicted by FEM only when the plastic deformation of the die is considered. 展开更多
关键词 Fatigue Behavior of Cemented Carbide die in Cold Forging of steel
下载PDF
Determination and Analysis of Hardenability for Hot-Forging Die Steels with Deep-Hardening
19
作者 ZHAO Gang JIANG Min +3 位作者 QIN Gao-wu HAO Shi-ming GU Rong DAI Jian-ming 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2000年第1期27-30,共4页
ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was m... ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was measured and the tempering resistance was studied.It was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring. 展开更多
关键词 HARDENABILITY deep-hardening steel hot-forging die steel tempering resistance
下载PDF
Effects of Lanthanum on Mechanical Properties of 5CrNiMo Forging Die Steel
20
作者 郝新 郭洪飞 +2 位作者 高文海 刘景顺 何智慧 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S2期254-257,共4页
The alteration of the strength, hardness and impact ductility of 5CrNiMo steel using three different additions of RE La element is studied in this paper. The mechanical properties of 5CrNiMo steel with RE La additions... The alteration of the strength, hardness and impact ductility of 5CrNiMo steel using three different additions of RE La element is studied in this paper. The mechanical properties of 5CrNiMo steel with RE La additions are be compared with that of the 5CrNiMo steel on the same heat-treatment condition without RE La element addition. The results show that the strength, hardness and impact ductility of 5CrNiMo steel will be improved obviously when the content of RE La element is proper, and as the content of RE La element is 0.033%(mass fraction), the 5CrNiMo steel has the best mechanical properties. 展开更多
关键词 forging die steel 5CrNiMo strength HARDNESS impact ductility rare earths
下载PDF
上一页 1 2 107 下一页 到第
使用帮助 返回顶部