Low Toughness and Embrittlement Phenomena in Steels

2015 ◽  
pp. 439-485
Keyword(s):  
High Temperature ◽  
Hydrogen Embrittlement ◽  
Fracture Surface ◽  
Liquid Metal ◽  
Surface Characteristics ◽  
Low Alloy Steels ◽  
Contributing Factors ◽  
Tempered Martensite ◽  
Alloy Steels ◽  
Strength And Ductility

This chapter describes the causes of cracking, embrittlement, and low toughness in carbon and low-alloy steels and their differentiating fracture surface characteristics. It discusses the interrelated effects of composition, processing, and microstructure and contributing factors such as hot shortness associated with copper and overheating and burning as occur during forging. It addresses various types of embrittlement, including quench embrittlement, tempered-martensite embrittlement, liquid-metal-induced embrittlement, and hydrogen embrittlement, and concludes with a discussion on high-temperature hydrogen attack and its effect on strength and ductility.

Surface Effects on Alloys Drilled by Electrochemical are Machining

1986 ◽  
Vol 200 (4) ◽  
pp. 237-246 ◽  
Author(s):  
A de Silva ◽  
J A McGeough
Keyword(s):  
Oxide Film ◽  
Smooth Surface ◽  
Surface Characteristics ◽  
Pulsed Power ◽  
Low Alloy Steels ◽  
Electrochemical Dissolution ◽  
Electro Discharge Machining ◽  
Water Based ◽  
Alloy Steels ◽  
Side Gap

Electrochemical arc machining (ECAM) utilizes pulsed power in an electrolyte, in order to remove metal by combined electro-discharge erosion (EDE) and electrochemical dissolution (ECD). In drilling by this technique, EDE occurs at the frontal gap between the cathode-tool and anode-workpiece; in the side gap, ECD is predominant. Machining rates are much greater than those of electrochemical (ECM) and electro-discharge machining (EDM). This paper is concerned with an investigation of the effects of EDE and ECD on the surface integrity of a range of alloys of industrial interest, drilled by ECAM. Chrome, cobalt and low-alloy steels and nickel-based (nimonic) alloys all exhibited a smooth surface finish typical of that found with ECM, for most of the length of the drilled hole, except at the exit. There, metallurgical damage due to EDE was apparent. The surface characteristics with titanium were typical of those found in EDM, with virtually no evidence of ECM action. This effect was attributed to the presence of a tenacious oxide film formed on titanium in water-based electrolytes which effectively blocks ECM.

Proposed New Fatigue Design Curves for Carbon and Low-Alloy Steels in High Temperature Water

2009 ◽  
Vol 131 (2) ◽  
pp. 024003
Author(s):  
William J. O’Donnell ◽  
William John O’Donnell ◽  
Thomas P. O’Donnell
Keyword(s):  
High Temperature ◽  
Low Alloy Steels ◽  
Fatigue Design ◽  
High Temperature Water ◽  
Alloy Steels ◽  
Temperature Water

Low-Alloy High-Strength Steel for Boiler Tubes (LowC-9Cr-2Mo)

1976 ◽  
Vol 98 (2) ◽  
pp. 173-178 ◽  
Author(s):  
T. Yukitoshi ◽  
K. Nishida ◽  
T. Oda ◽  
T. Daikoku
Keyword(s):  
High Temperature ◽  
High Strength Steel ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Steel Tube ◽  
High Temperature Strength ◽  
Low Alloy Steels ◽  
Service Test ◽  
Alloy Steels

High-strength steel tube HCM9M (LowC-9Cr-2Mo) steel, which shows the intermediate high-temperature strength between austenitic stainless steels and commercial low-alloy steels, has been developed. It has superior weldability, workability and oxidation resistivity. At present HCM9M tubes have been in-service test as reheater and superheater tubing at the 165,000 kW boiler in Japan without trouble. This report deals with the practical properties of HCM9M steel, service test experience and high temperature strengthening mechanism of the steel from morphological viewpoint of carbide.

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