Operational Degradation of Spheroidal Graphite Cast Iron EN GJS SiMo

2017 ◽  
Vol 270 ◽  
pp. 27-33
Author(s):  
Břetislav Skrbek
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Critical Temperature ◽  
Spheroidal Graphite ◽  
Temperature Structure ◽  
Cast Irons ◽  
Alloyed Cast ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Operational Degradation

The specifics of low-alloyed cast irons after EN 16124 standard of type GJS SiMo for high temperature applications of exhaust tracts of internal combustion piston engines. Boundary exposition temperature. Structure failure of cast iron by temperature overloading. Metalography, SEM, XRD of overexposed exhaust pipelines. Failure reason hypothesis of useful properties by exceeding of critical temperature.

Semisolid Forging of Cast Iron Using Rapid Resistance Heating

2007 ◽  
Vol 561-565 ◽  
pp. 925-928 ◽  
Author(s):  
Seijiro Maki ◽  
Kazuhito Suzuki ◽  
Kenichiro Mori
Keyword(s):  
Cast Iron ◽  
Control Function ◽  
Electric Energy ◽  
Spheroidal Graphite ◽  
Pig Iron ◽  
Resistance Heating ◽  
Cast Irons ◽  
Ac Power ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Feasibility of semisolid forging of cast iron using rapid resistance heating was experimentally investigated. Gray pig iron FC250 and spheroidal graphite cast iron FCD600, whose carbon equivalents are both 4.3% in mass, were used for the experiments. Since these cast irons have a narrow semisolid temperature range, an AC power supply with an input electric energy control function was used. In this study, the resistance heating characteristics of the cast irons were firstly examined, and then their semisolid forging experiments were conducted. In the forging experiments, the conditions of the forgings such as microstructures and hardness properties were examined, and the feasibility of the semisolid forging of cast iron using resistance heating was discussed. As a result, it was found that the method presented here is highly feasible.

Experimental Investigation of Twist Fatigue Characteristics on Piston Rings

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
E. Pavithra ◽  
Mahesh Dhakal ◽  
Prithvi Hada ◽  
N. Yuvaraj ◽  
K. Sridhar
Keyword(s):  
Cast Iron ◽  
Internal Combustion Engines ◽  
Piston Ring ◽  
Spheroidal Graphite ◽  
Piston Rings ◽  
Cast Irons ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Grey Cast ◽  
Fatigue Characteristics

Piston ring is one of the most important parts of the internal combustion engines. This paper investigates the mechanical and twist fatigue characteristics on different piston ring materials. The piston ring materials were chosen in this study such as grey cast irons (3740 and 6140), malleable cast iron (3929), spheroidal graphite cast iron (6139) and martensitic carbidic grey cast iron (6454). Twist fatigue test was conducted on different materials of piston rings in order to identify the suitable piston ring for the effective operation. Geometrical features and the mechanical properties were also assessed in different materials for the effectiveness of piston rings.

Suppression of Elevated Temperature Brittleness in Spheroidal Graphite Cast Iron by Increasing Phosphorus Content

2010 ◽  
Vol 457 ◽  
pp. 428-432
Author(s):  
Yoshitaka Iwabuchi ◽  
Isao Kobayashi
Keyword(s):  
Cast Iron ◽  
Elevated Temperature ◽  
Phosphorus Content ◽  
Marked Decrease ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Low Phosphorus ◽  
Fracture Appearance

Elevated temperature brittleness (ETB) of spheroidal graphite (s-g) cast iron has been referred to as reduced ductility within an elevated temperature range and has been related to grain boundary brittleness. The phenomenon of ETB has not been yet clearly understood. In this study, the factor affecting on ETB was studied in terms of strain rate and chemical composition. A study was carried out on the influence of phosphorus on ETB by using laboratory-made heats containing different phosphorus contents. ETB indicated the marked decrease in ductility at around 673K. S-g cast iron containing low phosphorus content manifested ETB at temperatures between 650K and 700K. There was a consistent correlation between the fractional increases in intergranular fracture appearance and the decrease in elongation. The increase of phosphorus suppressed ETB and s-g cast irons containing phosphorus exceeding 0.030 % were found to be immune to ETB. It was found that ETB could be suppressed by reducing the ratio of magnesium and phosphorus to less than 1.5.

High Temperature Corrosion of the Si-Mo Cast Iron in Exhaust Atmosphere

2008 ◽  
Vol 595-598 ◽  
pp. 743-751 ◽  
Author(s):  
Kamel Dawi ◽  
Jérôme Favergeon ◽  
Gérard Moulin
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Corrosion Products ◽  
Critical Conditions ◽  
Spheroidal Graphite ◽  
Exhaust Gas ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Gas System ◽  
Experimental Parameters

The SiMo cast iron is a spheroidal graphite cast iron which major alloying elements are silicon and molybdenum. This alloy is currently used in diesel engines as part of exhaust gas system like exhaust manifold or turbocharger housing components. It is then designed to work at high temperature under corrosive atmosphere. However, this alloy presents sometimes unusual high corrosion rates, and it is thus advisable to define the critical conditions leading to this type of problem. In the present study, the SiMo cast iron is tested in complex atmospheres containing N2, O2, SO2, CO2 and H2O in a temperature range lying between 300°C and 600°C. SEM observations and EDX and XRD analyses allow to qualify the nature of the corrosion products. Some thermodynamic calculations complete the experimental results. Three experimental parameters are especially studied in this work: the temperature of the isothermal corrosion tests, the presence of water vapour and the SO2 content in the gas mixture. The main results show that the corrosion products are metallic sulphides, sulfates and oxides. When sulphides and / or sulfates are present, the corrosion scale does not ensure a sufficient protection of the substrate and it is necessary to find conditions where only oxides are present. Such conditions are obtained for the highest temperature used in this study (600°C), or with highly oxidant atmospheres.

Tensile Deformation of Cast Iron During Pearlite :Austenite Transformation

1984 ◽  
Vol 34 ◽  
Author(s):  
A. Hazotte ◽  
A. Simon
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Metal Forming ◽  
Tensile Deformation ◽  
Structural Evolution ◽  
Spheroidal Graphite ◽  
Thermomechanical Cycling ◽  
Heating And Cooling ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

ABSTRACTRemarkable elongations have been obtained on cast iron samples subjected to alternate thermal cycles around the A1 critical point, under a tensile stress lower than the yield stresses of the stable phases. This procedure makes use of the “phase transformation plasticity”, characterised by an apparent softening of the material during its structural evolution. The influence of the applied stress, as well as the heating and cooling rates,on the elongation per cycle has been studied. A quantitative comparison between this “soft” technique and the more classical high-temperature metal forming techniques (deformation in stable α or γ domains, or in α + γ domain, high temperature creep) showed that, for an equal strain, the internal cavitation resulting from the thermomechanical cycling deformation of spheroīdal graphite cast iron is much smaller than for other techniques. This soft technique leads to higher mechanical characteristics at room temperature.

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