Interpretation of significant decrease in cryogenic-temperature Charpy impact toughness in a high manganese steel

TiC base high manganese steel-bonded carbide was manufactured with conventional powder metallurgy method to service in wear and impact resistant condition. WC was added in the alloy in the form of (W,Ti)C carbides to improve the impact toughness and expand the applications of alloy, meanwhile, cobalt powder was also used to enhance the wettability of the metallic binder on the ceramic phase. Results showed that the impact toughness of the alloy was increased remarkably with the increase of WC content. The impact toughness reached 10.6 J/cm2 when WC content was 10.5 wt.%, while the hardness of the alloy did not decrease. It was indicated that the appropriate content of WC and cobalt can improve impact toughness and wear resistance of the alloy greatly with little increase in the production cost.

Download Full-text

Study on the Mechanical Behavior and Microscopic Mechanism of Explosive Working of High-Manganese Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.506 ◽

2011 ◽

Vol 239-242 ◽

pp. 506-512

Author(s):

Cheng Gang Ding

Keyword(s):

Surface Hardness ◽

Residual Deformation ◽

Charpy Impact ◽

Charpy Impact Test ◽

Manganese Steel ◽

High Manganese ◽

High Manganese Steel ◽

Microscopic Mechanism ◽

Abrasive Resistance ◽

Metallographic Structure

This paper has examined the hardening effect and mechanism of explosive working on high-manganese steel. According to the experiment result, the surface hardness of high-manganese steel is improved greatly after explosive working and the hardened depth exceeds 40mm. The surface hardness and hardened depth increase slightly, the tensile strength is improved and ductility is reduced after three times of explosion. Charpy impact test demonstrates that it has still high ductility, the fatigue performance isn’t inferior to that before the explosion, the abrasive resistance is higher than that before the explosion and macroscopic residual deformation is extremely small. Such changes are related with the internal stress and changes of metallographic structure after explosion. After explosion, the surface is at stress state and the metallographic structure still retains the single-phase austenite matrix; and it produces high-density dislocation, stacking fault, cross-slip, lattice torsion, twin-crystal and refinement of austenite crystal grains.

Download Full-text

Ratio Mn:C and impact toughness of high manganese steel

Metal Science and Heat Treatment ◽

10.1007/bf00707649 ◽

1986 ◽

Vol 28 (4) ◽

pp. 251-255

Author(s):

S. E. Kondratyuk ◽

B. B. Vinokur ◽

G. G. Lutsenko ◽

O. G. Kasatkin

Keyword(s):

Impact Toughness ◽

Manganese Steel ◽

High Manganese ◽

High Manganese Steel

Download Full-text

Investigation of Correlation Between Fracture Toughness and Charpy Impact Energy of Cryogenic Steel Welds

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19251 ◽

2021 ◽

Vol 21 (9) ◽

pp. 4921-4925

Author(s):

Gyubaek An ◽

Seunglae Hong ◽

Jeongung Park ◽

Ilwook Han

Keyword(s):

Fracture Toughness ◽

Charpy Impact ◽

Manganese Steel ◽

Unique Element ◽

Crack Tip Opening Displacement ◽

High Manganese ◽

Opening Displacement ◽

High Manganese Steel ◽

Steel Welds ◽

Cryogenic Steel

The high manganese steel was developed to improve the fracture toughness and safety at cryogenic temperatures, the austenite structure was formed by increasing the manganese (Mn) content. The developed weld high manganese steel was alloyed with austenite stabilizing elements (e.g., C, Mn, and Ni) for cryogenic toughness and fluxes contained less than 10% of acidic slag formers such as rutile (TiO2) and silica (SiO2). This paper describes the work carried out to enhance the fracture toughness of Mn contents in an economical way by means of increase of manganese up to 23% instead of using nickel (Ni) which has unique element to improve fracture toughness especially at cryogenic steel. The new cryogenic steels should be carefully evaluated in terms of safety for application in real structures including LNG ships. In this study, the fracture toughness performance was evaluated for recently developed cryogenic steels (high-Mn steels), especially the crack tip opening displacement (CTOD) parameter was evaluated using the prediction formula proposed by conventional equation. The CTOD value was investigated the effect of microstructure and mechanical properties of Fe–C–Mn and Fe–C–Mn–Ni high manganese steel, it was revealed that the e-martesnsite phase formed in high manganese steel of 0.2C–20Mn and 0.4C–20Mn as a result of a low stability of austenite upon strain-induced phase transformation.

Download Full-text