• List of Articles تمپر

      • Open Access Article

        1 - Investigation of the Tempering Treatment on the Mechanical Propertiesof 13%Cr Super Martensitic Stainless Steel
        Saeeid Jbarzare Iman Kheirollahi-Hoseinabadi S. M Sehri Rasol Ghasemi محمد Kuwaiti ابراهیم Shokraneh
        The samples wear tempered at 520-720 °C for 3-10 h and air cooling to investigate the effect of tempering treatment on microstructural evolution and mechanical properties of13%Cr SuperMartensitic Stainless Steel. After heat treatment, hardness and tensile strength t More
        The samples wear tempered at 520-720 °C for 3-10 h and air cooling to investigate the effect of tempering treatment on microstructural evolution and mechanical properties of13%Cr SuperMartensitic Stainless Steel. After heat treatment, hardness and tensile strength tests were performed for investigation of mechanical properties. Moreover, optical microscopy and scanning electron microscopy (SEM) were performed for investigation of microstructure observations. X-Ray diffraction (XRD) was carried out to measure of austenite retained in the samples. The results indicated that the optimization of mechanical properties were achieved by austenitizing treatment at 1050 °C for 1 h and water quenching and then tempering treatment at 600 °C for 3 h with air cooling.The results indicated that the optimization of mechanical properties were achieved by austenitizing treatment at 1050 °C for 1 h and water quenching and then tempering treatment at 600 °C for 3 h with air cooling.The results indicated that the optimization of mechanical properties were achieved by austenitizing treatment at 1050 °C for 1 h and water quenching and then tempering treatment at 600 °C for 3 h with air cooling. Manuscript profile
      • Open Access Article

        2 - Investigating the Effect of Al Temper type on Microstructure and Mechanical properties of Al 6061/Mg AZ31 alloys Diffusion Bonded Joint
        مجتبی جعفریان علیرضا خدابنده مرتضی جعفریان
        In this study, the effect of Al alloy temper type on the microstructure and mechanical properties of Al 6061 (T6,O) and Mg AZ31 (O) were investigated. The interface of joints was investigated by optical microscope (OM) and Scanning Electron Microscope (SEM) equipped wit More
        In this study, the effect of Al alloy temper type on the microstructure and mechanical properties of Al 6061 (T6,O) and Mg AZ31 (O) were investigated. The interface of joints was investigated by optical microscope (OM) and Scanning Electron Microscope (SEM) equipped with EDS and Linescane analysis. Mechanical properties of joints were measured by using a Vickers microhardness and shear strength tests. According to the results, in Al 6061-O/Mg AZ31 joint, less plastic deformation in the Mg alloy, further diffusion rate of Mg atoms in the Al alloy and the formation of diffusion region with the lowest amount of microhardness (140 HV) and the highest amount of shear strength (32 MPa) was occurred compared to Al 6061-T6/Mg AZ31 joint. Evaluation of fracture surfaces indicates the occurrence of the failure in brittle phase of Al3Mg2. Manuscript profile
      • Open Access Article

        3 - Investigation of microstructure and mechanical properties of AISI304L Stainless Steel to ASTMA514 Steel joint by Gas Tungsten Arc Welding
        موسی توکلی عباس سعادت محمدرضا خانزاده قره شیران
        In the present study, Dissimilar welding of austenitic   stainless steel AISI 304L to Quenched and Tempered Steel ASTM A514 was investigated by gas tungsten arc welding process. Two filler metals including (ERNiCr-3) and austenitic stainless steel 309l (ER309L More
        In the present study, Dissimilar welding of austenitic   stainless steel AISI 304L to Quenched and Tempered Steel ASTM A514 was investigated by gas tungsten arc welding process. Two filler metals including (ERNiCr-3) and austenitic stainless steel 309l (ER309L) were used. Microstructure of nugget, heat affected zone, inter face and unmixed zone (UMZ) was studied by optic microscopy and scanning electron microscopy equipped with energy disperse spectrometry (EDS). The investigations showed completely austenitic structure as dendrite for ERNiCr-3 weld metal and primary ferrite with austenitic matrix for 309l weld metal. Mechanical properties including tensile and bending strength, impact resistance, hardness and fractography of the specimen was studied. The entire specimen underwent ductile fracture in HAZ in the tension test. Tensile strength in ER309L and ERNiCr-3 had increment of 556 Mpa and 593 Mpa respectively. Impact thoughtless in join induced by ERNiCr-3 filler was 117 J while it was 95 J for ER309L. The maximum and minimum hardness was related to the ERNiCr-3 (156 Vickers) and ER309L (127 Vickers), respectively. Finally, according to mechanical properties, it can be concluded that in dissimilar welding of austenitic stainless steel AISI 304 L to Quenched- Tempered Steel ASTM A514, The ERNiCr-3 filler is better than ER309L. Manuscript profile
      • Open Access Article

        4 - Evaluating the effect of deep cryogenic heat treatment on microstructure, wear and tension properties of the GOST9HF-steel at tempering temperature from 150 to 650˚C
        kamran amini
        In recent years, cryogenic-treatment is considered in order to improve of wear and hardness resistance of tool steels. Cryo-treatment is performed on steel before and after of tempering and quenching treatment, respectively. In this research, the effect of deep cryogeni More
        In recent years, cryogenic-treatment is considered in order to improve of wear and hardness resistance of tool steels. Cryo-treatment is performed on steel before and after of tempering and quenching treatment, respectively. In this research, the effect of deep cryogenic treatment is investigated on the GOS9HF-steel. In this regard, the quenched-tempered and quenched-Cryo-treated samples are prepared after tempering treatment for 2hrs. then, impact of Cryo-treatment on value of retained austenite, fine carbide precipitations are evaluated by XRD, SEM and the amount of hardness, strength and wear resistance are measured by micro-hardness, tensile and wear tests. The wear test is conducted by pin-on-disc method. The results indicated that the amount of hardness and properties of wear and tensile in the Cryo-treated sample were rather than the quenched-tempered samples at all of tempering temperatures (i.e. from 150 to 650˚C). Additionally, with increase of tempering temperature, the amount of hardness, wear behavior and tensile property are decreased in both of Cryo-treated and quenched-tempered samples. This can be attributed to the softening of microstructure and the growing of grain sizes. Moreover, it was obvious that improving of Cryo-treated samples are related to the removing of retained austenite, precipitation of fine carbides and more appropriate distribution of these carbides. It is cleared that the Cryo-treatment causes to decrease of value of retained austenite from 12% to below of 1% at quenched-tempered and Cryo-treated samples, respectively. Finally, Cryo-treatment causes to increase of volume fracture of carbides to 52%. Manuscript profile
      • Open Access Article

        5 - Evolution of the Microstructure and Mechanical Properties of Friction Stir Welded Ferrite-Martensite DP700 Dual Phase Steel
        Mahdi Mahmoudiniya Amir Hossein Kokabi Massoud goodarzi
        In present research, the effect of tool transverse speed on the microstructure and mechanical properties of friction stir welded DP700 dual-phase steel has been studied. Welding process conducted at a rotational speed of 800 rpm and tool transverse speeds of 50 and 100 More
        In present research, the effect of tool transverse speed on the microstructure and mechanical properties of friction stir welded DP700 dual-phase steel has been studied. Welding process conducted at a rotational speed of 800 rpm and tool transverse speeds of 50 and 100 mm/min. Optical and scanning electron microscopy were used for microstructural examinations, and mechanical properties were evaluated using microhardness measurements and tensile test. Microstructural investigation revealed that the stir zone consists of bainite, acicular ferrite and polygonal ferrite. It was also revealed that the heat-affected zone (HAZ), based on the peak temperature (Tp), can be subdivided into three different regions: 1) inner HAZ, where Tp is higher than Ac3, 2) Middle HAZ, where Tp lies between Ac1 and Ac3, 3) Outer HAZ in which Tp is lower than Ac1. It was also found that the martensite phase tempers in OHAZ and the degree of tempering decreases with the increment of tool transverse speed. This results confirmed by microhardness measurements where the hardness reduction of the softened zone decreased from 28 to 20HV with an increment of tool transverse speed. The highest hardness of the joints corresponded to the stir zone, and its value increased from 345 to 375HV with rising tool transverse speed. Tensile test results showed that the ultimate strength of the joints was lower than the base metal (723MPa) and it increases from 662 to 671MPa with rising tool transverse speed. It was also revealed that increasing transverse speed improves the total elongation by 2.6%. Manuscript profile
      • Open Access Article

        6 - Investigation of the Intergranular Corrosion Behavior of UNS S42000 Martensitic Stainless Steels Using Potentiodynamic Electrochemical Impedance Spectroscopy
        Khashayar Morshed-Behbahani Pooria Najafisayar Mahmoud Pakshir Nika Zakerin
        In this research, UNS S42000 martensitic stainless steel (SS) samples were subjected to tempering heat treatment at constant temperature of 550 oC for different time duration, ranging between 0.5 and 24 h, so as to assess the intergranular corrosion (IGC) behavior of th More
        In this research, UNS S42000 martensitic stainless steel (SS) samples were subjected to tempering heat treatment at constant temperature of 550 oC for different time duration, ranging between 0.5 and 24 h, so as to assess the intergranular corrosion (IGC) behavior of the alloy. The microstructural characteristics and electrochemical properties of the alloys were evaluated using scanning electron microscopy (SEM) and anodic polarization method, respectively. The localized attack of the samples was investigated by potentiodynamic electrochemical impedance spectroscopy (PD-EIS) in the transpassive potential region. The results indicated that tempering up to 2 h would be followed by severe intergranular attack at martensite lath interfaces; however, the effect of tempering on corrosion performance of the alloys would be suppressed at prolonged tempering due to desensitization. Moreover, the PD-EIS results revealed that the charge transfer resistance (Rct) values of specimens at 1.10 V can be employed as a primary criterion in order to assess the localized attack of the martensitic SS. In this regard, the lower the Rct value at this DC bias potential, the lower the corrosion resistance to the IGC. These results were in good agreement with the SEM morphologies from the surfaces of corroded samples, indicating uniform corrosion, severe attack and desensitization for samples experiencing no-tempering, short tempering time and prolonged tempering, respectively. Manuscript profile