Prediction of Mechanical and Toughness Properties of Ni-Modified Cr-Mo Alloy Steels for Transmission Gear

2021 ◽  
Vol 56 ◽  
pp. 1-15
Author(s):  
Hailemariam Nigus Hailu ◽  
Daniel Tilahun Redda
Keyword(s):  
Fracture Toughness ◽  
Impact Toughness ◽  
Yield Strength ◽  
Alloy Steel ◽  
Surface Hardness ◽  
Tempering Temperature ◽  
Ann Modeling ◽  
Ni Content ◽  
Alloy Steels ◽  
Transmission Gear

The purpose of the study was to predict the mechanical and toughness properties of Ni-modified alloy steels by adding 1.55%, 1.75%, and 1.95% of Ni-content to the existing Cr-Mo alloy steel of transmission gear material. Typically transmission gears have been working under severe working situations of loads and rotations. Due to these situations, the properties and qualities of gear materials are highly affected consequently, fatigue failure is instigated. So, improving the mechanical and toughness properties of the existing gear material is very vital and compulsory since these properties have a direct impact on gear fatigue failure. Investigations have been done on determining the mechanical and toughness properties of the Ni-modified Cr-Mo alloy steels, through ANN modeling prediction by associating the complex relation of input (chemical composition, tempering temperature) and output parameters (mechanical and toughness properties), and verified by experimental test approaches. Explored these materials property with ANN modeling and experimental test show that the more Ni-content added to the Cr-Mo alloy steel, the higher the ultimate and yield strength can achieve at every instant of tempering temperature. Likewise, fracture toughness, impact toughness, and percent of retained austenite of these materials were also investigated thoroughly as tempering temperature varies. Thus, a 1.55 % Ni-modified Cr-Mo alloy steel has a higher value of both impact toughness and fracture toughness compared with other Ni-modified alloy steels. Similarly, surface hardness was slightly decreased as the amount of Ni-content added increased at each instant of tempering temperature. Lastly, based on both predicted and experimental results, 1.55 % of Ni-modified Cr-Mo alloy steel showed a better combination of mechanical and toughness properties. Keywords: ANN modeling; Yield strength; Ni-modified; Tempering temperature; Fracture toughness; Surface hardness

ALLOY STEEL 4520

Alloy Digest ◽  
1979 ◽  
Vol 28 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Yield Strength ◽  
Physical Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
Section Thickness ◽  
Tempering Temperature ◽  
Steel Mills ◽  
Molybdenum Steel

Abstract Alloy Steel 4520 (Nonstandard, formerly AISI-SAE 4520) is a 0.50% molybdenum steel well suited for use in carburized and non-carburized applications. It has a yield strength of around 50,000 psi in the normalized condition and from 50,000 to 65,000 psi in the quenched and lightly tempered condition (depending on section thickness and tempering temperature). Its uses include railway cars, bridge construction and carburized parts such as gears. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-357. Producer or source: Alloy steel mills and foundries.

RUUKKI RAEX 300

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Shear Strength ◽  
Impact Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Structural Components ◽  
Wear Resistant

Abstract RUUKKI RAEX 300 (typical yield strength 900 MPa) is part of the Raex family of high-strength and wear-resistant steels with favorable hardness and impact toughness to extend life and decrease wear in structural components. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on wear resistance as well as forming, machining, and joining. Filing Code: SA-643. Producer or source: Rautaruukki Corporation.

Failure Mechanism of Ultra-High Pressure Fluid Control Products

2014 ◽  
Vol 703 ◽  
pp. 381-384
Author(s):  
Xin Long Chen
Keyword(s):  
Electron Microscopy ◽  
Impact Toughness ◽  
Failure Mechanism ◽  
Oil And Gas ◽  
Surface Hardness ◽  
Tempering Temperature ◽  
Inclusion Content ◽  
Ultra High Pressure ◽  
Oil And Gas Fields ◽  
Gas Fields

The square elbows used in oil and gas fields were often failed because of serious erosion. Some of the products even burst. In this paper, the failure mechanism of square elbow was investigated by using electron microscopy (OM), electron microscopy (SEM) methods. The research results show that the elbow products failed due to its low impact toughness after carburizing and quenching. The erosion angle is nearly ninety-degree. By increasing the tempering temperature, reducing the surface hardness and improving toughness, the serious erosion phenomenon can be effectively avoided. There are two main reasons of the elbow products burst. One reason is the high inclusion content of the material. The other is the low impact toughness. Raising the quality specification of materials can appropriate increase the low impact toughness after heat treatment. It is pointed out that the product would be more safety by improve its impact toughness.

scholarly journals Effect of Tempering Temperature on Microstructures and Wear Behavior of a 500 HB Grade Wear-Resistant Steel

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 45 ◽  
Author(s):  
Erding Wen ◽  
Renbo Song ◽  
Wenming Xiong
Keyword(s):  
Electron Microscopy ◽  
Wear Resistance ◽  
Impact Toughness ◽  
Wear Behavior ◽  
Temper Embrittlement ◽  
Surface Hardness ◽  
Resistant Steel ◽  
Tempering Temperature ◽  
Wear Resistant ◽  
The Impact

The microstructure and wear behavior of a 500 Brinell hardness (HB) grade wear-resistant steel tempered at different temperatures were investigated in this study. The tempering microstructures and wear surface morphologies were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The relationship between mechanical properties and wear resistance was analyzed. The microstructure of the steel mainly consisted of tempered martensite and ferrite. Tempered troosite was obtained when the tempering temperature was over 280 °C. The hardness decreased constantly with the increase of tempering temperature. The same hardness was obtained when tempered at 260 °C and 300 °C, due to the interaction of Fe3C carbides and dislocations. The impact toughness increased first and reached a peak value when tempered at 260 °C. As the tempering temperature was over 260 °C, carbide precipitation would occur along the grain boundaries, which led to temper embrittlement. The best wear resistance was obtained when tempered at 200 °C. At the initiation of the wear test, surface hardness was considered to be the dominant influencing factor on wear resistance. The effect of surface hardness improvement on wear resistance was far greater than the impact toughness. With the wear time extending, the crushed quartz sand particles and the cut-down burs would be new abrasive particles which would cause further wear. Otherwise, the increasing contact temperature would soften the matrix and the adhesive wear turned out to be the dominant wear mechanism, which would result in severe wear.

Mechanical Properties of SA508 Gr.4N Model Alloys as a High Strength RPV Steel

2010 ◽  
Author(s):  
Min-Chul Kim ◽  
Ki-Hyoung Lee ◽  
Bong-Sang Lee ◽  
Whung-Whoe Kim
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Impact Toughness ◽  
Power Plants ◽  
Charpy Impact ◽  
Alloying Elements ◽  
Low Alloy Steels ◽  
Charpy Impact Toughness ◽  
Age Related ◽  
Alloy Steels

Demands of RPV materials with higher strength and toughness are rising to increase the power capacity and the operation life of nuclear power plants. The ASME SA508 Gr.4N specification can give a superior toughness and strength to the commercial low alloy steels such as SA508 Gr.3. However, the SA508-Gr.4N steels have not yet been used commercially due to a lack of information of the productivity and the age related properties. While the irradiation embrittlement studies are going-on, the current paper focused on the effects of alloying elements such as Ni, Cr and Mo on the fracture mechanical properties of the SA508 Gr.4N low alloy steels. Various model alloys were fabricated by changing the contents of alloying elements based on the composition range of the ASME specification. Tensile properties, Charpy impact toughness and fracture toughness of the model alloys were evaluated and those properties were discussed with the microstructural characteristics of each alloy. The strengths of the alloys were increased with increase of the Ni and Mo contents while there was no remarkable change of the yield strength with the Cr addition. The Charpy impact and fracture toughness were considerably improved with the increase of Ni, Cr contents. The Mo addition did not change the toughness properties significantly. The Cr contents were more effective on the fracture toughness through changing the carbides precipitation characteristics and the Ni contents were effective on the Charpy impact toughness through changing the effective grain size.

Mechanical Properties of a Medium Carbon Low Alloy Steel Processed by Two Step Austempering Process

2010 ◽  
Vol 638-642 ◽  
pp. 3453-3458 ◽  
Author(s):  
Susil K. Putatunda ◽  
Abhijit Deokar ◽  
Gowtham Bingi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Yield Strength ◽  
Alloy Steel ◽  
High Yield ◽  
Bainitic Steel ◽  
Low Alloy Steel ◽  
High Yield Strength ◽  
Medium Carbon

A new bainitic steel with a combination of exceptionally high yield strength and fracture toughness has been developed. This steel has been synthesized by austempering a medium carbon low alloy steel by a novel two-step austempering process. The influence of this two-step austempering on the microstructure and the mechanical properties of this new steel have been examined.

Alternative Approach for Qualification of Temperbead Welding in the Nuclear Industry

2012 ◽  
Author(s):  
Steven L. McCracken ◽  
Richard E. Smith
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Alloy Steel ◽  
Nuclear Power ◽  
Post Weld Heat Treatment ◽  
Nuclear Power Industry ◽  
Low Alloy Steels ◽  
Low Alloy Steel ◽  
Alloy Steels ◽  
Weld Heat

Temperbead welding is common practice in the nuclear power industry for in-situ repair of quenched and tempered low alloy steels where post weld heat treatment is impractical. The temperbead process controls the heat input such that the weld heat-affected-zone (HAZ) in the low alloy steel is tempered by the welding heat of subsequent layers. This tempering eliminates the need for post weld heat treatment (PWHT). Unfortunately, repair organizations in the nuclear power industry are experiencing difficulty when attempting to qualify temperbead welding procedures on new quenched and tempered low alloy steel base materials manufactured to modern melting and deoxidation practices. The current ASME Code methodology and protocol for verification of adequate fracture toughness in materials was developed in the early 1970s. This paper reviews typical temperbead qualification results for vintage heats of quenched and tempered low alloy steels and compares them to similar test results obtained with modern materials of the same specification exhibiting superior fracture toughness.

REPUBLIC HP 150

Alloy Digest ◽  
1964 ◽  
Vol 13 (11) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
Heavy Plate ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition

Abstract Republic HP150 is an alloy steel designed to give 150,000 psi yield strength with exceptional toughness. The alloy is intended for fabrication in the heat treated condition principally for heavy plate sections. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-170. Producer or source: Republic Steel Corporation.

scholarly journals Influence of Charge Quality on Physical, Mechanical and Operational Properties of Low-Alloy Steel 30KHGSA

2020 ◽  
Vol 24 (2) ◽  
pp. 17-36
Author(s):  
N. N. Sergeev ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
I. V. Tikhonova ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Alloy Steel ◽  
Relative Elongation ◽  
Temper Brittleness ◽  
Low Alloy Steel ◽  
Cross Sectional ◽  
Tempering Temperature ◽  
Working Length ◽  
The Impact

Purpose of reseach is to study the influence of the quality of the original charge on the complex of physical, mechanical and operational properties of structural low-alloy steel 30HGSA.Methods. As an object of research, a typical representative of low-alloy structural steels has been chosen - steel 30HGSA, smelted using metallized sponge iron pellets, ordinary scrap metal and billets obtained by the method of a boiling slag layer. In accordance with the set objectives of the study, steel 30HGSA of various melts, obtained with different charge, had the same conditions for melting, evacuation, deoxidation, casting and crystallization. The casting temperature was 1600...1620 оC and the post-vacuum treatment temperature was 1530...1560 °C. Duration of evacuation - 5 minutes. Casting of melts was carried out into cast iron molds with a siphon for 4 ... 5 minutes. Deoxidation was carried out in a ladle with aluminum in the amount of 4 ... 4.5 kg / melt. After solidification, the ingots were cooled in special wells. The ingots were cut into 3 parts: head, middle and bottom (600 × 600 mm). The middle part was then hot forged and rolled to a Ø30 mm bar. The length of the rod was 2 ... 3.4 m. After hot deformation, the rods were cooled in air.Results. Mechanical tests have been carried out. Statistical processing of experimental results has been performed. Regularities of changes in the characteristics of mechanical properties have been revealed: tensile strength, creep strength, relative narrowing of the cross-sectional area of the sample, relative elongation of the initial working length, impact strength (σВ, σ0.2, ψ, δ, aН).Conclusion. It has been found that with an increase in temperature, the mechanical properties of steel 30HGSA, smelted on various charges, decrease. It has been established that the cold brittleness threshold of 30HGSA steel is lower for purer melts on spongy iron and intermediate product KShS, the value of impact toughness at low temperatures is higher than in melting on a conventional metallized charge. Noticeable softening begins at a tempering temperature of 300 °C The temperature of the maximum tempering brittleness for steel 30HGSA, melted on a conventional metallized charge, is 550 °C It is shown that steel 30HGSA smelted with a pure original charge (spongy iron) has a lower tendency to temper brittleness than steel smelted with a conventional charge. The value of the impact toughness of the steel of this melt is higher than that of the steel of conventional melting over the entire tempering temperature range.

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