A Study on the Microstructure and Hardness Feature of 6CrW2MoVSi Steel after Heat Treatment

2014 ◽  
Vol 887-888 ◽  
pp. 223-227
Author(s):  
Yu Mei Dai ◽  
Yong Qing Ma ◽  
Yan Bin Wu ◽  
Ya Nan Ji
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Precipitation Hardening ◽  
Middle Section ◽  
Temperature Quenching ◽  
Quenching Temperature ◽  
Tempering Temperature ◽  
Higher Temperature ◽  
Average Size

6CrW2MoVSi steel has a refined and even microstructure after heat treatment, the average size of annealing carbide is 0.6 μm; quenching martensite is mainly lath-shaped martensite and only a small amount of acicular martensite, and the size of quenching acicular at 950 °C is smaller than 2.5 μm. The curve of quenching hardness increasing with quenching temperature rising is divided into three sections. In the middle section of quenching between 910 °C ~ 980 °C, quenching hardness presents slow rising trend. After higher temperature quenching, there are low and high temperature tempering precipitation hardening zones. At 220 °C ~ 240 °C tempering temperature, precipitation hardness is HRC54 ~ 58. At 540 °C ~ 570 °C tempering temperature, precipitation hardness is HRC52 ~ 56.

The Influence of Heat Treatment on Microstructure and Properties of 00Cr15Ni7Mo2Cu2 Supermarteniste Stainless Steel

2011 ◽  
Vol 399-401 ◽  
pp. 211-215
Author(s):  
Yong Heng Zhou ◽  
Kun Yu Zhao ◽  
Xin Liu ◽  
Dong Ye ◽  
Wen Jiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Lath Martensite ◽  
Temperature Quenching ◽  
Quenching Temperature ◽  
Austenite Grain Size ◽  
Tempering Temperature ◽  
Grain Sizes ◽  
Austenite Grain ◽  
Different Temperatures

There are lath martensite and a little austenite in the microstructure of samples quenched. The original austenite grain sizes ranges from 7.9μm to 74.1μm, which grows up gradually with the increasing of temperature quenching. So do the martensite acicular bundle. During the process of tempering at different temperatures after quenching at 1050°C, austenite grain size becomes bigger with the temperature increasing, and martensite acicular bundle becomes thinner. The content of austenite ascends to the peak at 650°C then it decreases. The mechanical properties (σb =958.87 MPa, δ=20.44%, HRC=30.9) of the samples are the best, when quenching temperature is 1050°C and tempering temperature is 600°C.

Preparation of Butadiene

1928 ◽  
Vol 1 (2) ◽  
pp. 208-210
Author(s):  
Stanley Francis Birch
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Liquid Phase ◽  
High Temperatures ◽  
Vapor Phase ◽  
Complex Mixture ◽  
Higher Temperature ◽  
Oil Gas

Abstract OF THE numerous methods available for the preparation of butadiene in the laboratory, those described by Thiele and by Ostromuislenskii are probably the most convenient. Both, however, suffer from the disadvantages which usually characterize operations at comparatively high temperatures; the exact conditions are difficult to find, the process is long and tedious, and finally involves the separation of the required material from a complex mixture. It has long been known that butadiene occurs in the various products obtained when oils are heated to a high temperature. Caventou first isolated butadiene in the form of its tetrabromide from illuminating gas, and Armstrong and Miller definitely established the presence of butadiene in the liquid obtained by compressing oil gas. The work of numerous later investigators has confirmed their results and has shown that the more drastic the heat treatment to which the oil is submitted the greater is the tendency for butadiene to be formed. For this reason vapor-phase cracking of petroleum, which is carried out at a much higher temperature than liquid-phase cracking, yields products specially rich in butadiene.

Observation of Ag Precipitate in CuAgZr Alloy during In Situ High Temperature TEM

2017 ◽  
Vol 263 ◽  
pp. 50-54
Author(s):  
Waraporn Piyawit ◽  
Panya Buahombura
Keyword(s):  
High Temperature ◽  
Heating Process ◽  
Minor Variation ◽  
Transmission Electron ◽  
Large Lattice ◽  
Dislocation Movement ◽  
Higher Temperature ◽  
Average Size ◽  
A Minor

CuAgZr alloy is a minor variation of CuAg alloy that is remarkably known for good combination of strength and electrical conductivity. Strengthening and conductivity enhancing of CuAgZr alloy is essentially proficient by the precipitation of Ag precipitates. The behavior of Ag precipitates at high temperature was investigated using in-situ transmission electron microscopy. These nanoscale Ag precipitates are formed in CuAgZr alloy during heating process with the average size of 5 nm. Growth of precipitates at higher temperature can be explained by the consumption of solute diffusing from smaller precipitates. Dislocation looping at high temperature would be the effects of a large lattice strain along matrix/precipitate interface that would retard the dislocation movement.

scholarly journals Evolution of non-metallic inclusions during heat treatment

2020 ◽  
Vol 117 (4) ◽  
pp. 408
Author(s):  
Chengsong Liu ◽  
Bryan Webler
Keyword(s):  
Heat Treatment ◽  
Size Distribution ◽  
Inclusion Size ◽  
Isothermal Heat Treatment ◽  
Number Density ◽  
Inclusion Composition ◽  
Steel Microstructure ◽  
Metallic Inclusions ◽  
Higher Temperature ◽  
Average Size

Isothermal heat treatment can not only modify steel microstructure, but also non-metallic inclusions. In this work, heat treatment experiments were conducted between 1373 and 1573 K (1100 and 1300 °C) to study the evolution of inclusion composition, morphology, and size distribution. Results showed that during the heat treatment at 1473 and 1573 K (1200 and 1300 °C), two main kinds of inclusions initially in the steel, CaS and MgO–Al2O3–CaO–CaS, gradually transformed to (Ca, Mn)S and MgO–Al2O3–(Ca, Mn)S inclusions, and some MgO–Al2O3–CaO inclusions also transformed to MgO–Al2O3–(Ca, Mn)S. At the lowest temperature studied, 1373 K (1100 °C), little change was observed. No significant changes in number density and area fraction of the measured inclusions were observed, while the average size of inclusions increased after the heat treatment. The extent of transformation of CaS, MgO–Al2O3–CaO–CaS and MgO–Al2O3–CaO inclusions increased with decreasing inclusion size and higher temperature.

Crack Disappearance by High-Temperature Oxidation of Alumina Toughened by Ni Nano-Particles

2009 ◽  
Vol 68 ◽  
pp. 34-43 ◽  
Author(s):  
Ana L. Salas-Villaseñor ◽  
José Lemus-Ruiz ◽  
Makoto Nanko ◽  
Daisuke Maruoka
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Oxidation Reaction ◽  
High Temperature Oxidation ◽  
Annealing Temperature ◽  
Nano Particles ◽  
Ni Nanoparticles ◽  
Temperature Oxidation ◽  
Oxidation Period ◽  
Higher Temperature

Crack disappearance by high-temperature oxidation was studied in alumina (Al2O3) composites toughened by Ni nanoparticles. This process is performed in air at temperature ranging from 1000 to 1300°C for 1 to 48 h. The results showed that crack disappearance depends on both annealing temperature and time. Complete crack disappearance in this composite was confirmed at lower temperatures for long oxidation period, 1100oC for 48 h, and higher temperature for shorter time, 1300oC for 1 h in air. The crack disappearance mechanism was explained on the basis of the formation of NiAl2O4 spinel on sample surfaces produced by the oxidation reaction during the heat treatment.

Heat Treatment of Wear Resistant Steels for Mud Pumps

2016 ◽  
Vol 870 ◽  
pp. 181-184 ◽  
Author(s):  
S.M. Nikiforova ◽  
M.A. Filippov ◽  
A.S. Zhilin
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
High Temperature ◽  
High Temperatures ◽  
Residual Austenite ◽  
Work Place ◽  
Temperature Quenching ◽  
Wear Resistant ◽  
Friction Hardening

Influence of different type heat treatment including high temperature quenching on wear resistance has been investigated. The two investigated steels are widely used in production of mud pumps. It was shown that Kh12MFL had better wear resistance in comparison with 150KhNML. Martensitic-carbide structure of the steels formed by quenching from high temperatures (900 – 1000 °С) induced good hardness (61 – 64 HRC). Analysis of the residual austenite contents influence on wear resistance was also made. It was determined that residual austenite formed after high temperature quenching (900 – 1000 °С) was metastable and had tendency to transform into carbon containing martensite of deformation. This allowed steels to have maximum wear resistance because of providing high abilities to friction hardening of the work place of the sample.

Phase Transformation of Coal at High Temperature

2014 ◽  
Vol 809-810 ◽  
pp. 815-821
Author(s):  
Xiao Hu Hua ◽  
Xiao Gang Wang ◽  
Jia Qing Yang ◽  
Shu He Lu ◽  
Li Rong Deng ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Composition ◽  
High Temperature ◽  
Internal Migration ◽  
Heat Treatment Temperature ◽  
Functional Group ◽  
Treatment Temperature ◽  
Conductive Phase ◽  
Higher Temperature

Anthracite and bitumite were processed respectively at 1400°C,1700°C, 2000°C, 2200°C, 2400°C and 2600°C,and their chemical composition,resistivity,microstructure, phase composition,and the internal migration of molecular functional group were tested and characterized. The results indicate that moisture, ash and volatile in coal have gradually shifted and lost with the elevation of heat treatment temperature, while the higher temperature, the quicker and completer phase change. Heat treatment can make the coal transform from approximately insulative phase to conductive phase,. Furthermore, as the temperature increases, the conductive phase transformation effect is better. The higher the heat treatment temperature of coal, the more amorphous carbon transforming into crystalline carbon completely, but the less types of phases .

ALLEGHENY D-979

Alloy Digest ◽  
1960 ◽  
Vol 9 (10) ◽  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Gas Turbine ◽  
Precipitation Hardening ◽  
Heat Treating ◽  
Temperature Performance ◽  
Hardening Heat Treatment

Abstract Allegheny D-979 is an austenitic, high-temperature superalloy for aircraft gas turbine applications. It responds to a precipitation hardening heat treatment. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-61. Producer or source: Allegheny Ludlum Corporation.

ARMCO 17-4 PH

Alloy Digest ◽  
1989 ◽  
Vol 38 (9) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Precipitation Hardening ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Excellent Corrosion Resistance

Abstract ARMCO 17-4 PH, a precipitation hardening stainless steel, is widely accepted in a broad range of industries. High strength, excellent corrosion resistance, ease of heat treatment and good weldability make it an important alloy to designers and engineers. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-7. Producer or source: Baltimore Specialty Steels Corporation. Originally published April 1953, revised June 1959, revised September 1989.

Effect of Heat Treatment on the Properties and Precipitations of High Strength Steel Plate for Construction Machinery

2014 ◽  
Vol 971-973 ◽  
pp. 240-243
Author(s):  
Tao Zhang ◽  
Hua Xing Hou ◽  
Zhao Tan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Strength Steel ◽  
Steel Plate ◽  
High Strength ◽  
Quenching Temperature ◽  
Tempering Temperature ◽  
Construction Machinery ◽  
Microstructure And Mechanical Properties ◽  
Tempering Resistance

The effect of heat treatment on the microstructure and mechanical properties of High Strength steel plate Q960E for construction machinery was investigated. The result shows the quenching temperature have obvious effects on the mechanical properties, DQ can improve the toughness and the enchance tempering resistance, precipitations become more and bigger with the rise of the tempering temperature.

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