Optimization of Heat Treatment Parameters of Mo-Free High-Cr Cast Iron Mill Balls

2007 ◽  
Vol 26-28 ◽  
pp. 913-916 ◽  
Author(s):  
Sang Mok Lee ◽  
Bong Hwan Kim ◽  
Je Sik Shin ◽  
B.M. Moon
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Impact Energy ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
High Impact ◽  
High Impact Energy ◽  
Surface Method ◽  
Designs Of Experiments ◽  
Proper Balance

A Mo-free high-Cr cast iron with superior impact-wear resistance was tried to develop for mill balls by alloy design and subsequent heat treatment. The Cr/C ratio was varied up to 7.7 in order to minimize and eventually eliminate Mo addition, still ensuring hardenability. For the proper balance between abrasion resistance and toughness, the combined effects of each heat treatment parameters on the mechanical properties were systematically investigated using Taguchi method and response surface method (RSM), well recognized as powerful tools of the designs of experiments (DOE). It was found that hardness and impact energy were mainly affected by tempering and destabilization conditions, respectively. It is noted that high impact energy of 5.2 J/cm2 was obtained without deteriorating hardness (54 HRc) during the verification experiments under the heat treatment condition optimized by the DOE analyses.

Optimization of post-weld heat treatment condition of arc-welded T91 steel tubes

2020 ◽  
Vol 188 ◽  
pp. 104213
Author(s):  
Ranjeet Kumar ◽  
Anand Varma ◽  
Y. Ravi Kumar ◽  
Himanshu Vashishtha ◽  
Jayant Jain ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
Post Weld Heat Treatment ◽  
Steel Tubes ◽  
Weld Heat

Effect of Heat Treatment Condition on the Characteristics of MnO2 Added-Fe2TiO5 Ceramics for NTC Thermistors Using Local Iron Oxide

2018 ◽  
Vol 917 ◽  
pp. 64-68
Author(s):  
Wiendartun ◽  
Jaenudin Kamal ◽  
Dadi Rusdiana ◽  
Andhy Setiawan ◽  
Dani Gustaman Syarief
Keyword(s):  
Heat Treatment ◽  
Iron Oxide ◽  
Treatment Condition ◽  
Treatment Time ◽  
Heat Treatment Condition ◽  
Heat Treatment Time ◽  
Second Phase ◽  
Room Temperature Resistivity ◽  
Electrical Characteristics ◽  
Ntc Thermistor

A study on the effect of heat treatment condition on the characteristics of MnO2 added-Fe2TiO5 ceramics for NTC thermistor has been carried out. The ceramics were produced by pressing an homogenous mixture of Fe2O3 (local/ yarosite), TiO2 and MnO2 (2.0 mole %) powders in appropriate proportions to produce Fe2TiO5 based ceramics and sintering the pressed powder at 1050 °C for 3 hours in oxygen gas. Some sintered pellets were heat treated by heating them at 300 °C for 5, 15 and 25 minutes in Ar + 7% H2 gas. The XRD analyses showed that the Fe2TiO5 ceramics with and without heat treatment time had orthorhombic structure. No peak from second phase was observed from the XRD profiles. From the electrical characteristics data, it was known that the heat treatment could change the electrical characteristics of the Fe2TiO5 based-thermistor. The thermistor constant (B) and room temperature resistivity (ρRT) decreased with the increasing of heat treatment time. All ceramics made had thermistor characteristics namely B = 3459-7596 K and ρRT = 1.056-6936.062 MΩcm. Thermistor constant of the ceramics was relatively big, indicated that ceramics made from local iron oxide in this work fit the market requirement for NTC thermistor.

Wear behaviors of WC and TiC on co matrix composites under three-body impact abrasive wear condition

2019 ◽  
Vol 71 (7) ◽  
pp. 893-900 ◽  
Author(s):  
Lei Dong ◽  
Xiaoyu Zhang ◽  
Kun Liu ◽  
Xiaojun Liu ◽  
Ruiming Shi ◽  
...  
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Impact Energy ◽  
Wear Behavior ◽  
High Impact ◽  
Impact Wear ◽  
High Impact Energy ◽  
Content Type ◽  
Three Body ◽  
The Impact

Purpose The purpose of this paper is to investigate the tribological properties of the WC/TiC-Co substrate under different loading conditions under three impact abrasive wear conditions. Design/methodology/approach The three body collisional wear behavior of Co alloy with WC and TiC at three impact energy was studied from 1 to 3 J. Meanwhile, the microstructure, hardness, phase transformation and wear behavior of these specimens were investigated by scanning electron microscopy, Rockwell hardness (HRV), EDS and impact wear tester. The resulting wear rate was quantified by electronic balance measurements under different pressures. Findings The specific wear rate increases with the increase of the nonlinearity of the impact energy and the increase in the content of WC or TiC. The effect of TiC on wear rate is greater than that of WC, but the hardness is smaller. The wear characteristics of the samples are mainly characterized by three kinds of behavior, such as cutting wear, abrasive wear and strain fatigue wear. The WC-Co with fewer TiC samples suffered heavier abrasive wear than the more TiC samples under both low and high impact energy and underwent fewer strain fatigue wears under high impact energy. Originality/value The experimental results show that the wear resistance of the Co alloy is improved effectively and the excellent impact wear performance is achieved. The results can be used in cutting tools such as coal mine cutting machines or other fields.

Effect of Post-Weld Heat Treatment on Hardness in Superduplex Stainless Steel ASTM A890/A890M - Grade 6A

2020 ◽  
Vol 1012 ◽  
pp. 296-301
Author(s):  
Clélia Ribeiro de Oliveira ◽  
Eloá Lopes Maia ◽  
Solange T. da Fonseca ◽  
Marcelo Martins ◽  
Julián Arnaldo Ávila Díaz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Arc Welding ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Superduplex Stainless Steel ◽  
Secondary Austenite ◽  
Welding Processes

Superduplex stainless steel alloy exhibit high mechanical and corrosion resistance, which main industrial application is in the petrochemical industry. The manufacture and maintenance of such equipment usually involve welding processes, followed by post-welded heat treatment and it often becomes impossible to apply heat treatments. Thereby, the purpose of this work is to verify the effect of a post-welded heat treatment on shielded metal arc welding in steel grade ASTM A890/A890M - grade 6A. The microstructure in the as-welded condition consisted of austenite, secondary austenite, and ferrite phases and, the post-welded heat treatment condition exhibited only austenite and ferrite. The hardness in the melt zone reached values of 300 HV after welding and, the value was reduced to 260 HV in the post-welded heat treatment condition.

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