Optimization of fatigue life distribution model and establishment of probabilistic S–N curves for a 165 ksi grade super high strength drill pipe steel

2016 ◽  
Vol 145 ◽  
pp. 527-532 ◽  
Author(s):  
Fei Liu ◽  
Shiming Zhou ◽  
Chengyu Xia ◽  
Dezhi Zeng ◽  
Taihe Shi
Keyword(s):  
Fatigue Life ◽  
Pipe Steel ◽  
Drill Pipe ◽  
High Strength ◽  
Distribution Model ◽  
Life Distribution

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

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.

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

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.

Investigations of Fatigue Performance of S135 Drill Pipe Steel under Uniaxial Loading

2013 ◽  
Vol 716 ◽  
pp. 418-422 ◽  
Author(s):  
She Ji Luo ◽  
Rong Wang ◽  
Kang Zhao
Keyword(s):  
Regression Analysis ◽  
Fatigue Life ◽  
Linear Correlation ◽  
Pipe Steel ◽  
Drill Pipe ◽  
Uniaxial Loading ◽  
Analysis Method ◽  
Compression Loading ◽  
Cracks Propagation ◽  
S135 Drill Pipe Steel

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.

Fatigue Reliability Functions

1989 ◽  
Vol 111 (4) ◽  
pp. 443-455 ◽  
Author(s):  
V. A. Avakov ◽  
R. G. Shomperlen
Keyword(s):  
Distribution Function ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Curve ◽  
Strength Distribution ◽  
Distribution Model ◽  
Fatigue Reliability ◽  
Life Distribution ◽  
Statistical Procedures ◽  
Two Parameter

There are many fatigue test and statistical procedures to establish the life distribution function Q = Q(N) at constant stress (S) level. But the stress distribution function, Q = Q(S), at specified life (N) is more important to the designer, and it remains less developed. Generally, if the fatigue life distribution Q(N) and fatigue curve S(N) equations are defined, the fatigue strength distribution Q(S) is implied. However, it has been shown [4, 6, 7, 9] that any life distribution model Q(N) may be transformed into the complicated strength distribution function Q(S). In this study orthogonal relations have been developed in order to predict complications and to resolve the problem under certain conditions. With the aid of the orthogonal relations strength distributions Q(S) have been deduced using (1) lognormal, (2) two-parameter Weibull, and (3) three-parameter logweibull life models Q(N).

Sign in / Sign up

Export Citation Format

Share Document