Study of the Impact Properties of Steel 25Mn

2011 ◽  
Vol 704-705 ◽  
pp. 1035-1040
Author(s):  
Da Yong You

The Charpy impact test、hardness test、microstructure and morphology analysis of impact fracture by SEM were introduced to research the difference of impact toughness on 25Mn, which were in the station of hot-rolled、normalized and quenched & tempered. The resulted showed that the changes of load、deformation and energy exhaust in difference stage of deformation and fracture could be gained by Charpy impact test. 25Mn in quenched & tempered has more deformation resistance and deformation property than which in other stations. The total impact values was 6J higher than which in normalized in average, however, the crack propagation values was 16.78J higher in average. Ductile-brittle property of the material can be estimated by the analysis of crack formation values、crack propagation values and fracture morphology on samples.

2014 ◽  
Vol 775-776 ◽  
pp. 296-301 ◽  
Author(s):  
Anderson de Paula Barbosa ◽  
Michel Picanço Oliveira ◽  
Giulio Rodrigues Altoé ◽  
Frederico Muylaert Margem ◽  
Sergio Neves Monteiro

The buriti (Muritia flexuosa) fiber are among the lignocellulosic fibers with apotential to be used as reinforcement of polymer composites. In recent years, the buriti fiber has been characterized for its properties as an engineering natural material. The toughness of buriti composites remains to be a evaluated. Therefore, the present work evaluated the toughness of epoxy composites reinforced with different amounts of buriti fibers by means of Charpy impact tests. It was found a significant increase in the impact resistance with the volume fraction of buriti fibers. Fracture observations by scanning electron microscopy revealed the mechanism responsible for this toughness behavior.


2012 ◽  
Vol 602-604 ◽  
pp. 2096-2099
Author(s):  
Min You ◽  
Ling Wu ◽  
Hai Zhou Yu ◽  
Jing Rong Hu ◽  
Mei Li

The effect of the shock temperature and time on the impact toughness of the adhesively bonded steel butt joint under Charpy or Izod impact test is studied using the experimental method. The results obtained show that the impact toughness decreases when the shock temperature increased. When the curing time, temperature as well as the open assembly time was set as constant, the higher the shock temperature is, the lower the impact toughness of the joint. Comparing to the Charpy impact test, the Izod impact test is more sensitive to the shock temperature. When the shock temperature is set at a value not less than 300 C, the impact toughness measured is nearly the same as zero due to decomposition, carbonization and volatilization of the adhesive.


2019 ◽  
Vol 18 (3) ◽  
pp. 297-306
Author(s):  
Cecep Slamet Abadi ◽  
Rosidi Rosidi ◽  
Idrus Assagaf

Welding technology is used because besides being easy to use, it can also reduce costs so it is cheaper. Especially for welding repair. From the welding repair the extent to which the strength of GMAW welds can repair components from the molded plastic mold room made of AISI 420 stainless steel. Repair of the print room components using deposit welding is tested using tensile strength and hardness as realization of resistance when holding the rate of liquid plastic entering the print room by 25 to 40 MPa, depending on the plastic viscosity, the precision of the mold and the filling level of the print room. Deposition welding method as a welding repair can affect a procedure to be able to produce a component that is safe and capable of being used in accordance with the provisions. The welding process used is reverse polarity GMAW DC with 125 A current and ER 70 S welding wire diameter 1.2 mm. Test material AISI 420. Tests carried out were tensile test, impact test and hardness test in weld metal, HAZ and base metal. From the Charpy impact test and tensile test obtained the value of welding strength which is close to the strength of the complete object, which is equal to 65%. The energy absorbed by the impact test object with GMAW welding is 5.4 Joule while for the whole test object is 8.1 Joule. The welding tensile strength is 520 MPa compared to the tensile tensile strength of 820 MPa.


2020 ◽  
Vol 12 (2) ◽  
pp. 168781402090456
Author(s):  
Guojun Wei ◽  
Chenglong Wang ◽  
Xingwang Yang ◽  
Zhenfeng Tong ◽  
Wenwang Wu

The mechanical performance of reactor pressure vessel materials is an important factor in the safety and economics of the operation of a nuclear power plant. The ductile-to-brittle transition temperature tested by Charpy impact test is the key parameter for evaluating the reactor pressure vessel embrittlement. In this article, the study of thermal aging embrittlement of temperature sets of reactor pressure vessel surveillance Ni-Cr-Mo-V steel weld metal was conducted by Charpy impact test. The thermal aging effect on the impact fracture behavior was analyzed. The impact test of the three batches of weld surveillance sample indicated that the weld metal embrittled during thermal aging. The study of impact fracture and Auger electron spectroscopy indicated that the element P segregated to the grain boundaries and lowered their cohesion strength during the long-term thermal aging. Therefore, the non-hardening embrittlement of Ni-Cr-Mo-V steel welds in a reactor pressure vessel caused by segregation of impurity elements P occurs during thermal aging.


2011 ◽  
Vol 183 ◽  
pp. 37-42 ◽  
Author(s):  
Janusz Cwiek ◽  
Jerzy Łabanowski ◽  
Santina Topolska ◽  
Maria Sozańska

The paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis; microstructure examinations with the use of light microscope, scanning electron microscope (SEM); mechanical properties examinations using the Charpy impact test, and Vickers hardness test; fracture mode evaluation with SEM.


Author(s):  
C.K. Agisparayan ◽  
K.O. Low ◽  
S.T. Lim ◽  
K.J. Wong

Background:Many studies were done to assess the mechanical characteristics of the bandage casts with regards to different specifications of materials under different parameters. Many patents have been designed on the various types of casting materials such as POP, fiberglass and polyester. A recent trend in the patent is to explore a hybrid combination for bandage casts to withstand structural failure, crack formation or deformation.Objective:This study aims to study the effect of impact force on plaster of Paris, fiberglass and hybrid bandage casts.Methods:There different bandage casts were constructed using plaster of Paris, fiberglass and a hybrid combination of plaster of Paris and fiberglass. They were subjected to Charpy impact test, three-point flexural test, and Rockwell B hardness test.Results:The impact characteristics, energy absorption properties, ductility, rigidity, strength, stiffness and indentation hardness of the hybrid bandage cast were found to be greatly influenced from being a composite of two casts and interfaces. It was found that the impact energy capable of being absorbed prior to fracture for the plaster of Paris, fiberglass and hybrid were 1.225 Joules, 11.125 Joules and 6.750 Joules, respectivelyConclusion:Hybrid bandage casts possessed improved impact characteristics compared to plaster of Paris bandage casts and more cost-effectiveness as compared to fiberglass bandage casts


2012 ◽  
Vol 174-177 ◽  
pp. 1030-1033 ◽  
Author(s):  
Guo Tao Cui ◽  
Zuo Cheng Wang ◽  
Tao Sun ◽  
Wei Min Guo ◽  
Jun Qing Gao

In this research, trace boron (4ppm, 8ppm, 11ppm) was added into the Nb-added HSLA H-beams. The impact toughness of H-beams with/without boron was examined by Charpy impact test (V-notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results prove that the absorbed impact energy at -40°C for the 4ppm, 8ppm, 11ppm boron-added steels respectively reaches up to 80J, 126J, 85J from 15J and H-beams with boron have a lower FATT than that without boron. It is also found that the total oxygen content affects the absorbed impact energy to a certain extent. It is discovered by transmission electron microscope (TEM) that boron mainly exists in solid solution state, except that a little amount of Fe23(C, B)6is formed at the grain boundaries, and the distribution of Nb(C, N) is also influenced by boron addition.


2013 ◽  
Vol 816-817 ◽  
pp. 13-17
Author(s):  
Lydia Sobotova ◽  
Miroslav Badida ◽  
Ľudmila Dulebová ◽  
Zdenka Dzoganova

Concerning with an actual situation in the exploitation of technological waste, this contribution deals with the properties analysis of moulded parts made of thermoplastics containing added regrind. The aim of the experiments was to analyze mechanical properties of plastics with various percentage of added regrind into basic material. Material PBT (polybutylene terephthalate), mineral composite with 30% glass fiber, was used for experimental testing. The plastics specimens were made by injection moulding and tested by chosen mechanical properties. The yield of tested material had tendency to decline with added amount of regrind. Addition of regrind had no impact on change of tensile strength and hardness of tested materials with regrind. The values of Charpy impact test had decreasing tendency with increasing rate of regrind. The utilization of regrind at the production of new moulded parts is important from aspect of reduction plastics waste and pollution abatement of environment.


2018 ◽  
Vol 280 ◽  
pp. 277-283
Author(s):  
C. Palanisamy ◽  
S. Kumar Selearajen ◽  
K. Siva

Industrialisation and the development of manufacturing process nowadays demand a more efficient and environmental friendly production. Microwave energy can be seen as the alternative heating application to meet the demands due to its ability to heat materials volumetrically. In this study, the usage of microwave energy to join thermoplastic is investigated. One of the key features of thermoplastic is the ability to shape when heated to their glass transition temperature and return to the moulded shape when it is cooled. Engineering thermoplastic Acrylonitrile-butadiene-styrene (ABS) was used as member while charcoal powder was used as susceptor material. The joining process was carried out with timing varying from 3 to 5 minutes, adhesive method and direct heating method. Upon the completion of joining, tensile test, 3 points test, hardness test and charpy impact test were conducted and compared to determine the strength of the joint.


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