Microstructure and Mechanical Properties of High Strength Low Alloy Steel Q550D

2021 ◽  
Vol 1035 ◽  
pp. 424-429
Author(s):  
Fang Po Li ◽  
Ning Li ◽  
Xian Lin Wang ◽  
Ming Hua Liang
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Oil And Gas ◽  
High Strength ◽  
Service Performance ◽  
Low Alloy Steel ◽  
Micro Structure ◽  
Gas Drilling ◽  
Drilling Equipment ◽  
Equipment Manufacture

Drilling equipment is the key of oil and gas drilling development. Its manufacturing quality and service performance have important influence on oil and gas drilling development safety. The application of high strength grade steel plays an important role in improving drilling equipment manufacturing level and service performance. In this paper, the chemical composition, microstructure, tensile properties, impact properties and hardness of TMCP Q550D and Q-T Q550D high-strength low-alloy steel were tested and compared, and the application feasibility for drilling equipment manufacture was analyzed comprehensively. The experimental results show that the mechanical properties of Q550D by two different methods were obviously higher than the requirement of national standard. Q550D steel had excellent plasticity and toughness, which meets the requirement of drilling equipment manufacture. The main difference between different steel lied in their chemical composition and micro-structure. Carbon content of TMCP Q550D steel plate was lower than that of QT Q550D, and TMCP Q550 was mainly depend on TMCP technology and micro-alloy elements, whose micro-structure was mainly granular bainite. Q-T Q550D was mainly depend on Q-T technology, and its microstructure was tempered sorbite with obvious banded structure and slightly low toughness.

STUDY OF HIGH-STRENGTH LOW-ALLOY STEEL WITH SUPER-EQUILIBRIUM NITROGEN CONTENT

2020 ◽  
pp. 3-13
Author(s):  
S.A. Krylov ◽  
◽  
A.A. Makarov ◽  
M.A. Druzhnov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Nitrogen Content ◽  
Mechanical Characteristics ◽  
High Strength ◽  
Low Alloy Steels ◽  
Low Alloy Steel ◽  
Joint Work ◽  
Alloy Steels ◽  
High Level

In continuation of joint work of FSUE «VIAM» and IMET RAN named after Baikov, in the field of obtaining low-alloy steels with increased mechanical properties with a super-equilibrium nitrogen content, the mechanical properties, structure, and chemical composition of the obtained steel were studied. It is shown that steel 10KH3A with a super-equilibrium nitrogen content (up to 0,2) electroslag remelting under pressure DESHP-0,1 (FSUE «VIAM») provides a high level of properties (ultimate strength 1670 MPa) while maintaining high mechanical characteristics (elongation 10%, constriction 50%).

Microstructure and Properties of Q690D High Strength Low Alloy Steel

2021 ◽  
Vol 1035 ◽  
pp. 418-423
Author(s):  
Fang Po Li ◽  
Ning Li ◽  
Cai Hong Lu ◽  
Ming Hua Liang
Keyword(s):  
Carbon Content ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Steel Plate ◽  
High Strength ◽  
Carbon Equivalent ◽  
Low Alloy Steel ◽  
Gas Drilling ◽  
Drilling Rig ◽  
Drilling Equipment

As one of the core equipment components of oil and gas drilling rig, derrick is also the main heavy-duty component. Working environment of derrick is quite bad, the material for which should have not only high strength, but also good plasticity, toughness and weldability. In this paper, the chemical composition, microstructure, tensile properties, impact properties and hardness of three typical Q690D high strength low alloy steel manufactured from different methods were studied. The application feasibility of Q690 for drilling derrick manufacture was analyzed. The experimental results show that the carbon equivalent, tensile properties and impact absorption energy of Q690D steel with different thickness obtained by TMCP and Q-T process were obviously higher than the requirement of corresponding standard. TMCP Q690D steel had better toughness, lower carbon content and carbon equivalent, and its micro-structure was granular bainite. Carbon content of Q-T Q690D steel plate was relatively higher than that of TMCP Q690D, and the toughness was slightly lower than that of TMCP Q690D. The microstructure Q-T Q690D was tempered sorbite, and there was certain zonal segregation in center part. The thickness of steel plate used in derrick was usually less than 40 mm, whose manufacturing technology of Q690D was mature. There is broad application prospect in the field of drilling equipment. The application of Q690D for drilling equipment not only improve the strength grade of equipment materials, but also help to optimize the design of components and ensure service safety.

scholarly journals Effect of enhanced weld cooling on the mechanical properties of a structural steel with a yield strength of 700 MPa

2020 ◽  
Vol 2 (11) ◽  
Author(s):  
Juhani Laitila ◽  
Lassi Keränen ◽  
Jari Larkiola
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Fatigue Strength ◽  
Impact Toughness ◽  
Yield Strength ◽  
Uniform Elongation ◽  
High Strength ◽  
Low Alloy Steel ◽  
External Cooling ◽  
Welding Processes

AbstractIn this study, we present the effect of enhanced cooling on the mechanical properties of a high-strength low-alloy steel (having a yield strength of 700 MPa) following a single-pass weld process. The properties evaluated in this study include uniform elongation, impact toughness, yield, tensile and fatigue strengths alongside the cooling time of the weld. With the steel used in this study, the enhanced cooling resulted in a weld joint characterized with excellent cross-weld uniform elongation, yield and fatigue strength. The intensified cooling reduced the time it takes for the weld to reach 100 °C by around 190 s. Not only the fusion line of the weld was less pronounced, but also the grain size of the CGHAZ was greatly refined as a result of the enhanced cooling. The results indicate that combining external cooling to the welding processes can be beneficial for the studied high-strength steel.

Spun Steel Pipes for the Offshore Industry

1983 ◽  
Vol 105 (1) ◽  
pp. 97-102 ◽  
Author(s):  
A. Royer ◽  
B. Dumas ◽  
M. Gantois
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Centrifugal Casting ◽  
High Strength ◽  
Controlled Rolling ◽  
Climatic Conditions ◽  
Casting Technique ◽  
Steel Pipes ◽  
Potential Applications ◽  
Offshore Industry

Many parts either for sea-line pipes as “buckle” or “crack arrestor,” or for structures may require the use of wall tubular products with high mechanical properties. Such heavy-wall pipes may be produced by centrifugal casting. Two Mn-Mo steels have been developed for medium-wall pipes (e≤35 mm) to be used under very severe climatic conditions: an acicular ferritic steel, a pearlite reduced steel produced by controlled rolling techniques [1, 2, 3]. More alloyed chemical composition and heat-treatments are needed to produce heavy-wall pipes. Then, production of such pipes is more difficult and sometimes impossible. Observations made on controlled-rolled Mn-Mo steel led to a better understanding of the influence of metallurgical structures and chemical composition on steel characteristics. Similar metallurgical structures can only be reached via other routes, for example centrifugal-casting of steel associated with heat-treatment, lead to the production of heavy-wall pipes with high strength and suitable transition temperature. After a brief description of the centrifugal casting technique, we introduce the grades developed for heavy-wall pipes with yield strength up to 100,000 psi. The mechanical properties, Battelle, fatigue, static bending, C.O.D., weldability, etc., of Centrishore II are given and compared to other materials. Possible offshore applications and other potential applications of parts produced by centrifugal casting are described.

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