Formation of structure and properties of complex alloy cast steel

Author(s):  
V.S. Muratov ◽  
E.A. Morozova ◽  
N.S. Yakimov

The patters of the effect of change in the chemical composition and modes of heat treatment on the structure and complex of mechanical properties of cast steel VKL-3 (12Kh2NVML) are studied. The experimental melting of steel with increased content of chromium, silicon, nickel and molybdenum is obtained. The steel of this composition has reduced ductility and toughness. At the same time, experimental steel melting makes it possible to the model segregation zones with increased content of alloying elements in the steel of typical composition that has chemical and structural heterogeneity and heterogeneity of ductility and toughness. It is shown that the use of the fi nal heat treatment with the adjusted modes (in particular, increased temperature and time of tempering) allows increasing the ductility of the steel to the required values, but the impact strength does not reach the required levels. The recommendations for maintaining of the alloying elements content near the lower allowable limit are given.

2012 ◽  
Vol 557-559 ◽  
pp. 34-37
Author(s):  
Jing Qiang Zhang ◽  
Jie Min Du ◽  
Ji Wei Guo ◽  
Shou Fan Rong ◽  
Guang Zhou Wang

The influences of Mn and heat-treatment technology on microstructure and mechanical properties of medium-carbon-low-alloy wear-resistant cast steel were investigated. The results show that the hardness first increases and then drops down with the increase of Mn content, and the best hardness is 54HRC with Mn content 1.5%. The impact toughness first increases and then drops down with the increase of Mn content. The hardness and impact toughness first increase and then drop down with the increases of quenching temperature. The optimal impact toughness can be obtaind by quenching at 920°C and tempering at 200°C. Part of lower bainite and residual austenite and mass of tempered martensite are obtaind after tempering.


2013 ◽  
Vol 419 ◽  
pp. 370-375 ◽  
Author(s):  
Ji Shan Li ◽  
He Ping Li ◽  
Biao Qiang Jiao ◽  
Bao Jia Lv ◽  
De Feng Chen ◽  
...  

In this paper, based the actual application condition of domestic and international brake disc for high-speed train, the low-alloy cast steel of the brake disc for high-speed train is developed. The chemical composition, melting and casting processes as well as heat treatment technology of disc material are studied. The new low-alloy cast steel has the ideal metallographic microstructure, proper physical and mechanical properties. The tensile strength is more than 1100Mpa in 20°C condition, the impact energy value (Aku2) is more than 8J in-60°C condition. The test results show the new low-alloy cast steel developed can meet the brake disc performance requirements for 380km/h high-speed train.


Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 172 ◽  
Author(s):  
Fei Zhang ◽  
Yang Yang ◽  
Quan Shan ◽  
Zulai Li ◽  
Jinfeng Bi ◽  
...  

Herein, the effects of height-diameter ratios (H/D) on the microstructure evolution and mechanical properties of 0.4C-Si-Mn-Cr steel during high temperature deformation are reported. The compression experiments were performed on steel samples using Gleeble to obtain a reasonable deformation temperature, and the degree of deformation was assessed in the range of 1.5 to 2.0 H/D via forging. The forged specimens were quenched using the same heat treatment process. The hardness and impact toughness of the steel samples were tested before and after heat treatment. Grain sizes gradually increased with an increase in the compression temperature from 950 °C to 1150 °C, and the grain sizes decreased with an increase in H/D. The microstructure of the steel samples contained pearlite, bainite, martensite, and retained austenite phase. The microstructure after forging was more uniform and finer as compared to that of as-cast steel samples. The hardness and impact toughness of the steel samples were evaluated after forging; hardness first increased and then decreased with an increase in H/D, while the impact toughness continuously increased with an increase in H/D. Hence, the microstructure and properties of steel could be improved via high temperature deformation, and this was primarily related to grain refinement.


2015 ◽  
Vol 641 ◽  
pp. 136-140
Author(s):  
Edyta Rożniata ◽  
Janusz Krawczyk ◽  
Robert Dąbrowski ◽  
Jerzy Pacyna

The subject of investigations constituted the G200CrNiMo4-3-3 cast steel applied for metallurgical rolls. This is the material, which microstructure can be modified by the heat treatment. The presented hereby work concerns the initial state (as cast condition) of the investigated cast steel. This cast steel constitutes the initial material for the heat treatment. The morphology of carbide precipitates, including the cementite precipitated on grain boundaries of the primary austenite, hypereutectoid cementite precipitated in the Widmannstӓtten system and lederburitic cementite, were characterised in the study. The results of investigations of mechanical and fractographic properties of the G200CrNiMo4-3-3 cast steel, were also presented. Among others, the values of fracture work in the impact test, fracture toughness (KIc) and wear resistance were given. The crack pathway together with the hypereutectoid cementite fraction role in its development, was presented. The obtained investigation results, presented in the hereby paper, will constitute the comparison base for the assessment of the heat treatment influence on the microstructure and properties of the tested G200CrNiMo4-3-3 cast steel.


2013 ◽  
Vol 762 ◽  
pp. 418-423
Author(s):  
Feng Zhang Ren ◽  
Feng Jun Li ◽  
Ling Bai ◽  
Yun Fei Wang

The heat treatment process of 31Mn2SiREB cast steel used in crawler shoes is directly lifted from the heat treatment process of Mn13 high-manganese cast steel, i. e., quenching at 1050 oC after casting. The reasonableness of the process needs to be surveyed. In this paper, the effects of quenching temperature and diffusion annealing pre-treatment on mechanical properties, micro-area composition uniformity and micro-hardness uniformity were investigated. For quenching after casting, the tensile strength and impact energy increase observably with the elevation of quenching temperature, but the impact energy at higher quenching temperature is still very small. The fluctuation of micro-hardness and chemical composition at different micro-areas becomes obviously small with the increase of quenching temperature. For quenching after a diffusion annealing pre-treatment, the impact energy is very high and up to 36.3 J.


2010 ◽  
Vol 146-147 ◽  
pp. 1009-1012 ◽  
Author(s):  
Ji Wen Li ◽  
Guo Shang Zhang ◽  
Shi Zhong Wei

A new wear resistance material named the hypoeutectic high carbon Fe-B cast steel with fine hard carbides dispersive distributed in the matrix have been investigated. The results show that the solidified structures of high carbon Fe-B steel consist of ferrite, pearlite and boride, and borides were distributed along grain boundary in interconnected network. After heat treatment, the metallic matrix changes into martensite and retained austenite. The eutectic borides are appeared to be less continuous network and isolated particles. The increasing of the quenching temperature leads to the improvement of hardness. Quenching at 980°C, impact toughness is increased with the increasing of the tempering temperature. The optimum heat treatment is quenching at 980°C(oil cooling) and tempering at 330°C(air cooling). The wear resistance of modified high carbon Fe-B cast steel is corresponding to Cr26 alloy. The impact wear mechanism is mainly plastic deformation and fatigue spalling.


2013 ◽  
Vol 712-715 ◽  
pp. 98-101
Author(s):  
Hong Bo Li ◽  
Jing Wang ◽  
Han Chi Cheng ◽  
Chun Jie Li ◽  
Xing Jun Su

This paper mainly through the experimental study on the heat treatment process and mechanical properties of cast steel 35CrMnSiMo.According to the effect of alloy elements in design of a high-toughness abrasion-resistant cast steel, Cr, Mn, Si, as the main alloy elements, supplemented by a small amount of Mo, the casting molding, for hardness and impact toughness test of mechanical properties of experimental steel. The results show that, the as-cast 35CrMnSiMo by 880 °C, quenching for 20min then, the same quenching temperature, quenching hardness of materials is far greater than the oil quenching hardness. Water quenching hardness up to 25% higher than the oil quenching hardness, The impact toughness of specimen is inversely proportional to the contrast relationship Hardness.


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