Effect Of Tempering Process Research Articles

Effect of tempering process on the structure and properties of M51/X32 bimetal band saw blade

Abstract The mechanical properties of band saw have a great influence on the cutting life. In this paper, through the systematic study of M51/X32 bimetallic band saw blade with different tempering temperatures and times, the metallography of the bimetallic band saw blade under different heat treatment conditions was analyzed. The mechanical properties of the bimetallic band saw blade under different conditions were tested. The results showed that the carbide in the metallography of the tooth tip was uniform and tended to be spherical when tempering at 600°C for five times. The mechanical properties such as hardness, tensile strength, and fatigue properties are well matched, which can extend the service life of bimetallic band saw blades and ensure the cutting quality.

Effect of tempering process on elastic modulus of soda-lime-silica glass

The tempering process strengthens the bending strength and impact strength of the glass, but it alters the elastic modulus of glass as well. Aim of this study is to investigate the variations in the elastic modulus of soda-lime-silica (SLS) glass after tempering. The elastic modulus of intact SLS glass is measured using the elastic support-free end beam test method. Additionally, the elastic modulus of broken SLS glass that had released the tempering stress is measured using nanoindentation. The experimental results show the tempering process reduces the elastic modulus of SLS glass, the reduction is related to the tempering level and glass thickness, the existence of tempered stress does not influence the elastic modulus of tempered SLS glass. Finally, the mechanism of variation in the elastic modulus of tempered glass is elucidated. Ignoring the effect of tempering will lead the elastic modulus of the SLS glass to be wrongly estimated.

Effect of tempering process on the cryogenic impact toughness of 13Cr4NiMo martensitic stainless steel

The effects of tempering process on the cryogenic impact toughness of 13Cr4NiMo martensitic stainless steel (13-4MSS) were investigated by experiments and crystal plasticity finite element modeling (CPFEM). The tempering structure mainly includes tempered martensite lath, reversed austenite and M23C6 carbide. The tempered martensite lath is refined by the tiny new martensite transformed by reversed austenite, and the refinement degree increases with the tempering temperature. The nucleation of reversed austenite depends on the new martensite and carbide generated during tempering, and more reversed austenite is obtained by double tempering. The cryogenic impact toughness of the material changes nonlinearly with the increase of tempering temperature. It indicates that fine martensitic lath and inverse austenite are beneficial to improve the cryogenic impact toughness of the material, while carbide particles play the opposite role. The results of CPFEM show that reversed austenite coordinates the impact force of the surrounding martensite through large plastic deformation, and eases the stress concentration. Reversed austenite even occurs DIMT behavior under large plastic deformation to further reduce the stress concentration and prevent the initiation and propagation of cracks. As a hard particle, carbide causes the stress concentration, leading to cracks initiation and propagation along the martensite boundary.

"Effect of tempering process on mechanical properties of high titanium microalloyed steels containing niobium "

"Effect of tempering process on mechanical properties of high titanium microalloyed steels containing niobium "

"Effect of tempering process on mechanical properties of high titanium microalloyed steels containing niobium "

"Effect of tempering process on mechanical properties of high titanium microalloyed steels containing niobium "

Effect of Tempering Process on Microstructure and Mechanical Properties of Low Alloyed Cast Steel

The effect of tempering process on the microstructure and properties of low alloyed cast steel was studied. The results show that tempered at (200~400)°C, the M/A island of the granular bainite decomposes and carbide precipitates. When the tempering temperature rises to (500~600)°C, the M/A island is completely decomposed, and the carbide aggregates and gradually spheroidizes. With the increasing of tempering temperature, the tensile strength increases first and then decreases, elongation and impact energy show a trend of increasing at first, then decreasing and then increasing. The tempering brittleness occurs at 400°C.

Effects of tempering process on microstructure and mechanical properties of ZG30Mn

Through microstructure analysis, hardness testing, tensile and impact tests, the effects of tempering process on the microstructure and mechanical properties of ZG30Mn were studied. The results show that the microstructure of ZG30Mn treated by different tempering processes is tempered sorbite. When the holding time is 60 min, with the increasing of the tempering temperature, the hardness and strength gradually decrease, and the elongation and impact energy gradually increase. When the tempering temperature is 600 °C, the hardness and strength of ZG30Mn gradually decrease with the prolongation of holding time, while the elongation and impact energy increase first and then decrease. According to the analysis, as the tempering temperature increases, the recovery and recrystallization of α-phase occurs and dispersed fine cementite gradually grows and spheroidizes, resulting in a decrease in hardness and strength, and an increase in elongation and impact energy. With the prolongation of holding time, the aggregation growth of alloy cementite results in the decrease of the elongation and the impact energy.

Effects of tempering process on microstructure and mechanical properties of G18NiMoCr3-6

In this article the effects of tempering temperature and tempering time on microstructure and mechanical properties of G18NiMoCr3-6 cast steel were studied. The results show that: the microstructure of G18NiMoCr3-6 treated by different tempering processes is tempered sorbite. When tempering temperature is within 510°C ∼630°C, the hardness and strength gradually decrease; the elongation and impact energy gradually increase with the increasing of the tempering temperature. The reason is that the tempering temperature increases the dislocation density decreases gradually, the martensite decomposes and the carbide precipitates, aggregates and grows. When G18NiMoCr3-6 is tempered at 600 °C for 60min∼120min, the microstructure is tempered sorbite. With the prolongation of holding time, the mechanical properties of G18NiMoCr3-6 changed little.

Effect of Tempering on Bendability and Impact Property of Hot Rolled Low-Carbon Martensitic Steel

We examined the effects of tempering process and alloying elements on the microstucture, tensile properties, bendability and impact property of direct quenched (DQ), and re-austenitizing and quenched (RQ) low-carbon martensitic steels. For this purpose, four low carbon martensitic steels (Fe-0.07C-1.8Mn-Cr-Nb-Ti-B) were selected. We have investigated the effects of tempering temperature and alloying elements of chromium (Cr), titanium (Ti) and niobium (Nb) on mechanical properties and microstructures. Mechanical properties and microstructures were analyzed as well using tensile test, V-bending test, charpy V-notched impact test and electron microscopy for DQ, DQ and tempered (DQ-T), RQ and RQ and tempered (RQ-T) low-carbon martensitic steels. It has been found that the as-quenched microstructures of the DQ and RQ specimens were fully martensitic structure. Prior austenite grain size and effective grain size after quenching were larger in the case of RQ steel. In both cases, tempering made the needle-shaped carbides. It is shown that the strength decreased when the tempering temperature increased. The strengths of the DQ and DQ-T steels were 30~50MPa higher than those of the RQ and RQ-T steels. Despite the higher strength of the DQ and DQ-T states, both had similar impact properties with the RQ and RQ-T states. However, the impact properties of the Nb added RQ and RQ-T steels with fine martensite morphology exhibited higher than those of DQ and DQ-T steels.

Effect of tempering process on microstructure and mechanical properties of G18NiMoCr3-6 cast steel

The effect of tempering process on the microstructure and mechanical properties of G18NiMoCr3-6 cast steel was investigated. The results show that the microstructure of G18NiMoCr3-6 cast steel is granular bainite after normalizing at 900°C, which consists of bainitic ferrite and isolated grain or strips (M/A) islands. (M/A) island decomposes, and carbide precipitates when the tempering temperature is 200-400° C. When the tempering temperature rises to 500-600° C, the (M/A) islands completely decompose, and the carbides aggregate and gradually spheroidize. With the increasing of tempering temperature, the hardness and yield strength and tensile strength gradually decrease, and elongation and impact energy show a trend of decreasing at first and then increasing. The tempering brittleness occurs at 200-400°C.

Structure–mechanical property relationship in a low carbon Nb–Cu microalloyed steel processed through a three-step heat treatment: The effect of tempering process

Abstract We describe here the impact of tempering temperature and tempering time on the microstructure and mechanical property in a low carbon Nb–Cu microalloyed steel via a three-step heat treatment. After tempering process, the microstructure primarily comprised of ferrite, retained austenite and tempered bainite/martensite. The ferrite matrix with ultrafine grain size was film-like and enriched with nanometer-sized niobium-containing and copper precipitates. The volume fraction of ferrite increased with the increase in tempering temperature and tempering time. Retained austenite had average grain size less than 1 μm and was enriched with copper precipitates that contributes to enhance the stability of austenite. The retained austenite revealed high thermal stability and remained stable in the range of 20–30% when tempering temperature and time changed. High strength and good ductility were obtained in the tempering temperature range of 450–550 °C, or by prolonging tempering time at 500 °C, where the yield strength was ~750 MPa and the product of tensile strength and % elongation was ~32 GPa%, which is attributed to the cooperation of multiphase microstructure, stable retained austenite and nanometer-sized precipitates.

Copper precipitation and its impact on mechanical properties in a low carbon microalloyed steel processed by a three-step heat treatment

The structure–mechanical property relationship, with particular focus on effect of tempering process on the microstructural evolution and mechanical properties was investigated in a low carbon Cu-bearing steel that was processed in three-steps, namely, intercritical annealing, intercritical tempering, and tempering heat treatment. The objective of adopting three steps was to elucidate the nature and evolution of microstructural constituents that contributed to high strength–ductility combination in the studied steel. The three-step processing led to a microstructure primarily comprising of ferrite, retained austenite, and small amount of bainite/martensite. The mechanical properties obtained were: yield strength>720MPa, tensile strength>920MPa, uniform elongation>20%, total elongation>30%, and low yield ratio of 0.78. The tempering step led to a significant increase in both yield and tensile strength and decrease in yield ratio, without reducing ductility, a behavior attributed to the precipitation of copper in retained austenite and ferrite. The precipitation of copper enhanced the stability of retained austenite and work hardening rate, leading to a high volume fraction of retained austenite (∼29%), with consequent increase in elongation and significant increase in yield and tensile strength during tempering.

Effect of Tempering Process on Structure and Properties of Super Martensitic Stainless Steel

Two types of super martensitic stainless steels (Cr13 and Cr15) were designed. The effect of tempering process on their microstructure, mechanical properties and corrosion resistance was studied. The results showed that the main microstructure of tested steels was tempered martensite and a small number of reversed austenite when specimens were tempered in temperature range of 550-750°C. The variation of mechanical properties corresponded to the austenite volume fraction well. Both the two types of steels displayed a favorable comprehensive mechanical properties after tempering at 650°C, their product of strength and elongation reached to 18.44GPa•% and 18.44 GPa•% respectively. With the best heat treatment process,tempered at 650°C after quenching at 1050°C,the corrosion resistance of 2# steel is more better than 1# steel.

Research on Tempering Process of LZ20Mn2 Seamless Pipe for Axle

In order to find out the effects of tempering process on properties of axle steel, the thesis analyzes the change trend of properties of LZ20Mn2 axle steel pipe with variation of tempering temperature. And SEM was used to observe and analyze the fracture. The results show that the strength and hardness of LZ20Mn2 axle steel drop gradually and its toughness and plasticity are increased when tempering temperature goes up. Change of material properties trends to slow down after tempering at 570 °C. From point view of toughness, the technology for the best quality LZ20Mn2 axle pipe steel is the one with quenching at 880 °C with temperature holding for 30min, and tempering at 530 °C with 90min holding temperature. After heat treatment, the microstructure is fine grain size tempered sorbite structure and has good plasticity and toughness, so it can meet the requirement of both high strength and high toughness for axle.

A Study on the Microstructure of Ultra Low Carbon Bainitic Steels by RPC Technique

The effect of tempering process on the microstructure of ultra low carbon bainitic (ULCB) steel produced by relaxation precipitation controlled phase transformation (RPC) has been investigated by transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD). The results showed that the final microstructure mainly contained lath-like bainitic ferrite, granular bainite and martensite-austenite (MA) constituent in ULCB steels. On tempering at 650°C a slight increase was detected in the effective grain size as the strain-induced precipitates pinned up the dislocation walls and subgrains. After tempering at 700°C, bainitic ferrite laths started to coarsen and polygonal ferrite occurred. The effective grain size of ULCB steels in as-rolled condition was 1.5 μm at the tolerance of 10o~15o measured by EBSD technique.

Computer simulation and control of solid state phase transitions during liquid phase sintering (LPS)

The structure–mechanical property relationship, with particular focus on effect of tempering process on the microstructural evolution and mechanical properties was investigated in a low carbon Cu-bearing steel that was processed in three-steps, namely, intercritical annealing, intercritical tempering, and tempering heat treatment. The objective of adopting three steps was to elucidate the nature and evolution of microstructural constituents that contributed to high strength–ductility combination in the studied steel. The three-step processing led to a microstructure primarily comprising of ferrite, retained austenite, and small amount of bainite/martensite. The mechanical properties obtained were: yield strength > 720 MPa, tensile strength > 920 MPa, uniform elongation > 20%, total elongation > 30%, and low yield ratio of 0.78. The tempering step led to a significant increase in both yield and tensile strength and decrease in yield ratio, without reducing ductility, a behavior attributed to the precipitation of copper in retained austenite and ferrite. The precipitation of copper enhanced the stability of retained austenite and work hardening rate, leading to a high volume fraction of retained austenite (∼29%), with consequent increase in elongation and significant increase in yield and tensile strength during tempering.