Common Defect Analysis for Large Section Special Steel Forging

2017 ◽  
Vol 898 ◽  
pp. 1208-1214
Author(s):  
Xin Li Wen ◽  
Jian Peng Gao ◽  
Yuan Guo La

In order to Figure the common defect in large section special steel forging and find the solution, systematic study was carried out on hundreds of large section special steel forgings in a domestic famous steel mill. The steels included: low-carbon steel Q345D/E, medium-carbon steel 27SiMn, high-carbon steel GCr15SiMn, stainless steel 20Cr13. Both the amount and type of all the defect in the above steel were calculated and analyzed. The results showed that the common defects of the steel were slags, inclusions, loose (cavity) and inner cracks. The evolution of the cavity in the ingot during forging process was simulated by a numerical simulation software Deform-3D. The inner cracks in Q345D/E and 27SiMn initiated after A→F+P transformation The cracks in GCr15SiMn formed after the precipitation of net-like proeutectoid carbides. The cracks in 20Cr13 formed after the precipitation of net-like carbides. The internal cause of the cracks was relevant to composition segregation and internal stress in the forging. The external cause was connected with effect of slow cooling. Based on the above study, a set of new process was proposed and put into industrial application, with the result that the qualified ratio of flaw inspection in the above steel mill was improved from 20% to above 87%.

2001 ◽  
Vol 81 (12) ◽  
pp. 2797-2808
Author(s):  
Rustem Bagramov, Daniele Mari, Willy Benoi

2019 ◽  
Vol 2019 (3) ◽  
pp. 29-37
Author(s):  
A.A. Polishko ◽  
◽  
L.B. Medovar ◽  
A.P. Stovpchenko ◽  
E.V. Antipin ◽  
...  

1967 ◽  
Vol 53 (11) ◽  
pp. 1342-1344
Author(s):  
Akira NAKAGAWA ◽  
Akihiro SUZUKI ◽  
Tadatsugu KISHIGAMI ◽  
Norio NAGAI

Alloy Digest ◽  
1991 ◽  
Vol 40 (3) ◽  

Abstract UNS No. G 10600 is a high-carbon steel of low hardenability. It may be used in the as-rolled, annealed, normalized or quenched and-tempered condition, depending on the desired properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-129. Producer or source: Carbon steel mills.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 466
Author(s):  
Pawel Szczepankowski ◽  
Natalia Strzelecka ◽  
Enrique Romero-Cadaval

This article presents three variants of the Pulse Width Modulation (PWM) for the Double Square Multiphase type Conventional Matrix Converters (DSM-CMC) supplying loads with the open-end winding. The first variant of PWM offers the ability to obtain zero value of the common-mode voltage at the load’s terminals and applies only six switches within the modulation period. The second proposal archives for less Total Harmonic Distortion (THD) of the generated load voltage. The third variant of modulation concerns maximizing the voltage transfer ratio, minimizing the number of switching, and the common-mode voltage cancellation. The discussed modulations are based on the concept of sinusoidal voltage quadrature signals, which can be an effective alternative to the classic space-vector approach. In the proposed approach, the geometrical arrangement of basic vectors needed to synthesize output voltages is built from the less number of vectors, which is equal to the number of the matrix converter’s terminals. The PWM duty cycle computation is performed using only a second-order determinant of the voltages coordinate matrix without using trigonometric functions. A new approach to the PWM duty cycles computing and the load voltage synthesis by 5 × 5 and 12 × 12 topologies has been verified using the PSIM simulation software.


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