Study on Nonmetal Inclusions in Ultra-Low Oxygen Spring Steel during Process

2013 ◽  
Vol 331 ◽  
pp. 508-512 ◽  
Author(s):  
Xiao Dong Wu ◽  
Rui Long Chen ◽  
Bo Xiao ◽  
Zhong Ying Wang
Keyword(s):  
High Speed ◽  
Complex Oxide ◽  
Spring Steel ◽  
Fatigue Properties ◽  
Low Oxygen ◽  
Refining Slag ◽  
Total Oxygen ◽  
Oxide Inclusions ◽  
High Basicity ◽  
Lower Melting Point

The inclusions in ultra-low oxygen spring steel during process were studied. Sufficient aluminium was used during tapping. The refining slag has high basicity and strong reducibility. The total oxygen is only 10×10-6 in billet and the oxide inclusions in the steel have finished the transformation during refining and some complex oxide inclusions are easy to remove at steelmaking temperature. Residual oxide inclusions in the steel are CaO-MgO-Al2O3 complex inclusions with a relatively lower melting point, which have a little deform-ability during hot-working and can improve the fatigue properties of high speed wheel steel effectively.

Development of 60Si2CrVNb High Tensile Strength Spring Steel

2013 ◽  
Vol 744 ◽  
pp. 379-382
Author(s):  
Xiao Dong Wu ◽  
Rui Long Chen ◽  
Bo Xiao ◽  
Zhong Ying Wang
Keyword(s):  
Tensile Strength ◽  
Complex Oxide ◽  
Spring Steel ◽  
Extension Rate ◽  
High Tensile Strength ◽  
Refining Slag ◽  
Total Oxygen ◽  
Quenching Temperature ◽  
Oxide Inclusions ◽  
Strength And Plasticity

A production process of high tensile strength spring steel is discussed in this paper. Sufficient aluminum was added into ladle during tapping and barium alloy was used in late refining process. It was found that the refining slag with high basicity is strongly deoxidized after refining, with total oxygen content being less than 10×10-6 in billet. Thus, the oxide inclusions in the steel is finished the transformation during refining and some complex oxide inclusions are remarkably removed at steelmaking temperature. The tensile strength over 2.0GPa and the extension rate up to 10% are obtained for the spring steel after quenching temperature at 900oC and tempering at 410 oC. So, the strength and plasticity of the steel are improved obviously.

Formation and Control of Inclusions during Steelmaking Process

2011 ◽  
Vol 52-54 ◽  
pp. 1681-1686 ◽  
Author(s):  
Yang Li ◽  
Zhou Hua Jiang ◽  
Shi You Yin ◽  
Ying Zhuang ◽  
Ming Li
Keyword(s):  
Oxygen Content ◽  
Bearing Steel ◽  
Spring Steel ◽  
Refining Process ◽  
Steelmaking Process ◽  
Total Oxygen ◽  
Total Oxygen Content ◽  
Oxide Inclusions ◽  
Deoxidation Process ◽  
Lf Refining

The variation of non-metallic inclusions and total oxygen contents in different steel grades were investigated by taking samples in steelmaking process, including gear steel, anchor chain steel, hard wire steel, bearing steel and spring steel. The inclusions mainly were Al2O3, MnS, and their composite inclusions in aluminum killed steel at the beginning of LF refining due to addition of FeAl alloy during the tapping from EAF and feeding of Al wire in LF process, and then Al2O3 inclusion changed to the Al2O3 - CaO composite inclusions after feeding of SiCa wire. The inclusions at the beginning of LF refining mainly were MnS, SiC and their composite inclusions in non-aluminum killed steel due to addition of the composite deoxidation and slagging agents (mainly including CaC2 and SiC) when EAF taping, while the inclusions in tundish mainly were MnS, CaO - SiO2 - Al2O3 composite oxide - sulfide inclusions. It is showed that the inclusions in bearing steel and spring steel samples were mainly globular oxide inclusions and silicate inclusions with higher rated results. Therefore, the refining process should be improved to remove globular oxide inclusions. The inclusions in molten steel were controlled by enhancing the diffusion deoxidation process, adjusting and controlling the basicity and composition of refining slags, respectively, and satisfactory results were obtained. The industrial test shows that the total oxygen content of the aluminum killed steel in the test heat after feeding wire reached the minimum value, which indicates that the optimized slag has a strong ability of absorbing Al2O3 inclusions. For non-aluminum killed steel, the total oxygen content was 0.0027 % to 0.0029 % in rolled products. The inclusions in the end of refining and rolled product were small and dispersed composite inclusions, and the separate Al2O3 inclusions can not be found in the non-aluminum killed steel after optimization of the refining process.

INLAND DURASPRING

Alloy Digest ◽  
1998 ◽  
Vol 47 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Tensile Properties ◽  
High Stress ◽  
High Strength ◽  
Spring Steel ◽  
Fatigue Properties ◽  
Light Truck ◽  
Suspension Systems ◽  
Spring Steels

Abstract Inland DuraSpring is a high-strength microalloyed spring steel for use in high stress coil springs for automobile and light truck suspension systems. This bar product offers significant improvements in tensile strength, fatigue properties, and fracture toughness compared to conventional spring steels. This datasheet provides information on composition, hardness, and tensile properties as well asfracture toughness and fatigue. Filing Code: SA-496. Producer or source: Ispat Inland Inc.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals Evolution Mechanisms of MgO·Al2O3 Inclusions by Cerium in Spring Steel Used in Fasteners of High-speed Railway

2015 ◽  
Vol 55 (5) ◽  
pp. 970-975 ◽  
Author(s):  
Li Jun Wang ◽  
Yan Qiang Liu ◽  
Qi Wang ◽  
Kuo Chih Chou
Keyword(s):  
High Speed ◽  
Spring Steel ◽  
High Speed Railway

Effect of Refining Slag on the Inclusions of Hard Wire Steel during Melting Process

2011 ◽  
Vol 217-218 ◽  
pp. 1174-1179
Author(s):  
Yang Li ◽  
Zhou Hua Jiang ◽  
Shi You Yin ◽  
Ying Zhuang ◽  
Ming Li
Keyword(s):  
Ternary Phase Diagram ◽  
Melting Process ◽  
Melting Zone ◽  
Refining Slag ◽  
Total Oxygen ◽  
Deformation Ability ◽  
Inclusion Shape ◽  
Wire Steel ◽  
Al2o3 Inclusion ◽  
Inclusions In Steel

The effect of the refining slag composition on the total oxygen content and inclusions in steel was investigated in 100 t UHP Electric Furnace – LF – Billet CC process. The test steel was 77B hard wire steel and Si-Mn alloy was used as the deoxidizer. Three types slag were used in the industrial tests, which including CaO-CaF2, CaO-CaF2 adding CaC and CaO-Al2O3 refining slag. The results shown that the lowest total oxygen contents of rolled bar can be gained using the CaO-CaF2 refining slag adding CaC, which is 0.0036%, while the total oxygen contents of rolled bar using CaO-Al2O3 refining slag is higher a little than the heats using CaO-CaF2 refining slag. The CaO-SiO2 and CaO-Al2O3-SiO2 compound inclusions with the size of about 5 μm are the main inclusions in the heats refining by the CaO-CaF2 refining slag in the rolled bar, but the pure, indeformable Al2O3 inclusion can also be found with the size of about 10 μm. The CaO-Al2O3-SiO2 and Al2O3-SiO2-MnO compound inclusions are the main inclusions in the heats refining by the CaO-CaF2-CaC refining slag, but most of the inclusion shape is irregular with bigger size of about 10 μm. Similar with the heat using CaO-CaF2 refining slag, the pure Al2O3 inclusion with edge angle can be found in the rolled bar. The inclusions in the rolled bar treated by CaO-Al2O3 refining slag are CaO-Al2O3-SiO2 compound inclusions, most of which are nearly globular shape with the relative small size of about 5 μm. All of the inclusions in rolled bar lie on the low melting zone in the CaO-Al2O3-SiO2 ternary phase diagram in the heats using CaO-Al2O3 refining slag. The similar condition appeared on the most of the inclusions in the heats using CaO-CaF2 and CaO-CaF2 refining slag adding CaC, while part of which are lied on the high melting zone. Therefore, considering of the plastic deformation ability, the CaO-Al2O3 refining slag is the best slag for the melting process of hard wire steel.

Effect of [Al]s, [Mg], [Ca] in Molten Steel on Inclusion Content for High Speed Wheel Steel during LF-VD Process

2014 ◽  
Vol 898 ◽  
pp. 60-63
Author(s):  
Yu Tang
Keyword(s):  
Fatigue Life ◽  
Molten Steel ◽  
High Speed ◽  
Refining Process ◽  
Fatigue Performance ◽  
Wheel Steel ◽  
Inclusion Content ◽  
High Basicity ◽  
Secondary Refining ◽  
Improve Fatigue

In order to improve fatigue life of wheel steel, LF-VD secondary-refining process is done with Al-deoxidation and slag of high basicity, high Al2O3 content and low oxidizing property. Inclusion content would be influenced by [Al]s, [Mg], [Ca] in molten steel. It is found that Al2O3 inclusions, which are the products of Al-deoxidation, would react with [Mg], [Ca] in molten steel to transform into CaO-MgO-Al2O3 complex inclusions, which is the key for the enhancement of fatigue performance for wheel steel.

112 Axial Loading Fatigue Properties of High Speed Tool Steel in Very High Cycle Regime

2009 ◽  
Vol 2009.46 (0) ◽  
pp. 23-24
Author(s):  
Hiroto YAMAMOTO ◽  
Kazuaki SHIOZAWA ◽  
Yuji SHIMATANI ◽  
Takashi YOSHIMOTO ◽  
Masato KOSHI ◽  
...  
Keyword(s):  
Tool Steel ◽  
High Speed ◽  
Axial Loading ◽  
Fatigue Properties ◽  
Very High

Effects of Water Jet Peening and Hardening Treatment on Fatigue Properties of SCr420

2009 ◽  
Author(s):  
Akira Shimamoto ◽  
Ryo Kubota ◽  
Sung-mo Yang ◽  
Dae-kue Choi ◽  
Weiping Jia
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Water Jet ◽  
Fatigue Properties ◽  
In Situ Observation ◽  
Axial Tensile ◽  
High Pressure Water Jet

An experimental study of high pressure water jet peening treatment on chromium steal SCr420 H3V2L2 is conducted to study the effects of cavitation impacts of high-speed water on fatigue crack initiation and propagation of notched specimens. There are six different kinds of specimens. First three kinds are treated with; only annealing, only water quenching, and only oil quenching. Other three kinds are treated with above heat treatment and water jet peening, respectively. An axial tensile fatigue tests’ condition is 260MPa maximum stress amplitude, 0 stress ratio and 10Hz frequency, while in-situ observation by SEM is employed. Although fatigue life of the specimens with annealing and water jet peening is shorter than that of only annealing, fatigue life of water and oil quenching with water jet peening specimens is obviously longer than those without water jet peening treatment. Water jet peening has increased residual stress inside the specimens on the latter case and raised their fatigue strength. In-situ observation on the crack tips approves above analysis.

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