Research on the fatigue properties of S135 drill pipe steel under a variety of conditions

The fatigue life of S135 drill pipe steel was investigated by means of tension-compression loading and torsion loading under uniaxial loading during the fatigue test. The quantitative formulas of fatigue life were obtained by regression analysis method, and the fatigue fracture mechanism was analyzed. The results show that a linear correlation was found between fatigue life and effective stress in the double logarithmic plots. Cracks initiated from the specimens surfaces under tension-compression loading as well as torsion loading. For the tension-compression fatigue and the torsion fatigue specimens, the main characteristics for cracks propagation were striations and sheares ripple marks, respectively.

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COLD-SPRAYED Al-COMPOSITE COATINGS ON S135 DRILL-PIPE STEEL

Materiali in tehnologije ◽

10.17222/mit.2020.089 ◽

2021 ◽

Vol 55 (3) ◽

pp. 337-345

Author(s):

Dongli Lv ◽

Kai Yang

Keyword(s):

Mechanical Properties ◽

Friction Coefficient ◽

Corrosion Rate ◽

Surface Morphology ◽

Corrosion Behavior ◽

Pipe Steel ◽

Composite Coatings ◽

Drill Pipe ◽

Al Composite ◽

S135 Drill Pipe Steel

Nine kinds of Al-composite coatings were cold sprayed on the S135 steel. The mechanical properties and microstructures of the coatings were analyzed and the corrosion behavior of the coatings was studied. The surface morphology of the coatings was observed. The porosity of the nine coatings was less than 1.52 %. A proper increase in the Zn powder could reduce the porosity. The thickness of a coating could be increased with an increase in Al2O3 and Zn. The hardness of a coating increased obviously after adding Al2O3. The friction coefficient of a coating decreased with the increase in Zn and Al2O3. The corrosion rate of the coatings decreased with an increase in Al and Al2O3.

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Study on Properties of Cold-Sprayed Al-Zn Coating on S135 Drill Pipe Steel

Advances in Materials Science and Engineering ◽

10.1155/2020/9209465 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Dongli Lv ◽

Tao Zhang ◽

Feiyang Gong

Keyword(s):

Bonding Strength ◽

High Speed ◽

Pipe Steel ◽

Drill Pipe ◽

Petroleum Industry ◽

Al Content ◽

Coating Surface ◽

Powder Particles ◽

S135 Drill Pipe Steel ◽

Powder Content

With the gradual depletion of shallow resources, the petroleum industry is developing toward ultradeep wells and high-speed drillings, and the problems of corrosion and erosion failure of drill pipe materials are becoming more and more serious. On the basis of not destroying the excellent mechanical properties of S135 drill pipe steel, three kinds of coatings, 20% Al-80% Zn, 30% Al-70% Zn, and 40% Al-60% Zn, are cold sprayed on S135 steel. The morphology of the coating is observed, and the bonding strength, porosity, hardness, and corrosion resistance of the coating are tested. Results show that the bonding mechanism between the powder particles and the substrate of the three coatings is mainly mechanical occlusion. From the substrate to the coating surface, the hardness value decreases gradually. With the increase of Al powder content, coating bonding strength increases, coating becomes more compact, and porosity decreases. Corrosion test results show that three coatings can protect the substrate. The density of corrosion products on the coating surface increased with the increase of the Al content. Corrosion potential of the three coatings is lower than that of the substrate, and the corrosion rate of the three coatings is lower than that of the substrate.

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Research on Fatigue Test of LZ20Mn2 Axle Pipe Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.2152 ◽

2010 ◽

Vol 44-47 ◽

pp. 2152-2156

Author(s):

Hong Lei Dong ◽

Zhong Guo Huang ◽

Qing Hua Yuan ◽

Jia Fan

Keyword(s):

Crack Initiation ◽

Fatigue Test ◽

Pipe Steel ◽

Test Method ◽

Fatigue Properties ◽

Dog Bone ◽

Slow Decline ◽

Ultrasonic Fatigue ◽

Dislocation Crack ◽

Closure Effect

The core of ultrasonic accelerate fatigue test is resonance, and specimens need resonating with the system. The ultrasonic fatigue test method was used to investigate the high cycle fatigue properties of LZ20Mn2 axle pipe steel. Tests were conducted on cylindrical dog-bone specimens, and all fatigue loadings were controlled by inputting vibration amplitude. The results showed that the S-N curve of LZ20Mn2 axle pipe steel presented a slow-decline shape and subsurface crack initiation. The fatigue fracture was observed by SEM. Two different crack initiation mechanisms were observed which were the mixed inclusions and dislocation. Crack closure effect played an important role at fatigue crack propagation area and the fracture mechanism was a typical plastic fracture.

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The Development and Experimental Study on High Strength and Toughness Drill Pipe Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.1024 ◽

2011 ◽

Vol 287-290 ◽

pp. 1024-1032

Author(s):

Feng Hu ◽

Li Hong Han ◽

Hang Wang ◽

Yao Rong Feng ◽

He Lin Li

Keyword(s):

Electron Microscopy ◽

Yield Strength ◽

Pipe Steel ◽

Drill Pipe ◽

Control Process ◽

High Strength ◽

Alloy Element ◽

Deep Wells ◽

Alloy Carbon ◽

The Impact

With the development of oil industry, the high strength-toughness drill pipe suited to the task of sour environment and ultra deep wells would be considered more and more important. A new drill pipe steel, which was designed with the proper decrease of C content and increase of Cr, Ni, Mo, Nb and V alloy element, was developed and studied in this study. Large deformation hot rolling technology was used to obtain ultrafine grains microstructure. The results showed that the yield strength of this new drill pipe steel had reached 150ksi with the impact toughness more than 150J, which can perfectly meet the “leak-before-break” crack principle. The new low-alloy carbon steel drill pipe in the controlled yield strength grade 150ksi showing excellent sulfide stress cracking resistance and strength-toughness have been developed. Based on the observation of scanning electron microscopy and transmission electron microscopy, several kinds of carbide particles including (Nb, Mo, V)C with nanometer scale, were distributed in tempered sorbite matrix. The objective of this work was to study the relationship between carbide precipitation and strength-toughness by optimizing element design, thermo mechanical control process and heat treatment of drill pipe steel.

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Research On The Requirement Of Impact Toughness For Petroleum Drill Pipe Steel Used In Critical Sour Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.1106 ◽

2011 ◽

Vol 284-286 ◽

pp. 1106-1110

Author(s):

Li Hong Han ◽

Feng Hu ◽

Hang Wang ◽

Yao Rong Feng ◽

He Lin Li

Keyword(s):

Impact Toughness ◽

Statistical Data ◽

Pipe Steel ◽

Drill Pipe ◽

Curvature Effect ◽

Leak Before Break

This paper presents the determining method of impact toughness of drill pipe steel used in critical sour environment. Leak-Before-Break fracture principle was adopted to deduce the requirement of drill pipe with different strength grades for impact toughness, which considered both factors, such as geometry size and curvature effect. The loss law of impact toughness was also experimentally measured which could act as a good supplement for Leak-Before-Break fracture principle. Statistical data revealed that this requirement of drill pipe steel for impact toughness could be fully realized through current industrial ability.

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Simulated Research on Hot Forming Mechanism of Sour Service Drill Pipe Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.704-705.266 ◽

2011 ◽

Vol 704-705 ◽

pp. 266-272

Author(s):

Mei Juan Hu ◽

Peng Wang ◽

Li Hong Han ◽

Xin Li Han

Keyword(s):

Constitutive Equation ◽

Hot Deformation ◽

Pipe Steel ◽

True Strain ◽

Drill Pipe ◽

Peak Stress ◽

True Stress ◽

Experimental Results ◽

Strain Rates ◽

Sour Service

The dynamic mechanical behaviors of as-cast sour service drill pipe steel under development during hot deformation were studied in this paper by using Gleeble-3500 thermal mechanical simulator. The compressions were carried out at the temperature of 900°C, 1000°C, 1100°C, 1200°C and strain rates of 10s-1, 1s-1and 0.1s-1. The compress degree was about 70%, and then the maximum true strain for each specimen was 1.2. The experimental results show that the peak stress was related to the compression temperatures and the strain rates. Through respectively analyzing and studying the true stress-true strain curves, the hot deformation constitutive equation and the deformation activation energy were obtained by regression analysis. The evolution of microstructures at various strain rates and temperatures was discussed. Experimental results can provide scientific basis for analyzing the hot deformation processes and controlling quality. Keywords: sour service drill pipe, hot compression, true stress-true strain, constitutive equation, microstructure

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Precipitation Behavior and its Effect on Strengthening of High Strength and Toughness Drill Pipe Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.587 ◽

2011 ◽

Vol 335-336 ◽

pp. 587-594

Author(s):

Feng Hu ◽

Li Hong Han ◽

Hang Wang ◽

Yao Rong Feng ◽

He Lin Li

Keyword(s):

Pipe Steel ◽

Rapid Development ◽

Drill Pipe ◽

High Strength ◽

Alloy Element ◽

Deep Wells ◽

Transmission Electron ◽

Alloy Carbide ◽

The Impact ◽

Leak Before Break

With the rapid development of oil industry, the high strength-toughness drill pipe suited to the task of sour environment and ultra deep wells would be considered more and more important. A new drill pipe steel, which was designed with the proper decrease of C content and increase of Cr, Ni, Mo, Nb and V alloy element, was developed and studied in this study. The results showed that the yield strength of this new drill pipe steel had reached 150ksi with the impact toughness more than 150J, which can perfectly meet the “leak-before-break” crack principle. Based on the observation of optical microscopy and transmission electron microscopy, several kinds of carbide particles including (Nb, Mo, V)C with nanometer scale, were distributed in tempered sorbite matrix. The objective of this work was to study the relationship between multiple alloy-carbide precipitation and mechanical property of this drill pipe steel.

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