Seamless Steel Pipe Research Articles

Switching Model Adaptive Predictive Control

The paper considers the results of an adaptive predictive control system implemented in a combustion furnace. The main goal is to optimize the temperature control replacing the existing PID. The furnace dynamic is strongly nonlinear, has an important delay and its behavior depends on the operating point. These characteristics make the system very attractive for implementing a controller that achieves a more precise temperature control. The application consists of a weighted predictive control with its parameters obtained indirectly from a recursive identification of the plant. The project was developed at Siderca - Argentina, a seamless steel pipe factory.

Further experimental study on the failure of fully clamped steel pipes

In the present study experimental data recorded from 226 impact tests on seamless mild steel pipes are reported. The pipe specimens with different geometries were fully clamped at both ends, and impacted transversely by rigid wedge-shaped indenters at the positions of mid-span, one-quarter span and very close to a support, respectively. In order to model the fully clamped boundary conditions, a special clamping system was designed to hold the pipe specimens rigidly at each end to prevent any significant inward displacements from the supports. The impact velocities ranged up to 10.69 m/s and caused large inelastic indentations for the lower values and at higher values a loss of integrity near the supports. Particular attention was paid to obtaining the threshold value of initial impact energy that caused the onset of material rupture. Discussion is made for the influences of pipe geometry, impact position and internal pressure on the critical value of initial impact energy.

Densification of iron-zirconium -boron-nickel powders under uniaxial hot pressing : T.Masumoto et al. (Tohoku University, Sendai, Japan.)

Cobalt-chromium alloys are known for their excellent wear resistance. Many studies on the wear behavior of these alloys were reported in literature. Nevertheless, microabrasive wear still lacks extensively investigation. Microabrasive wear behavior, of three experimental cobalt alloys, was investigated: Alloy 1 similar to Stellite 250, 48 wt% Co, 29 wt% Cr, 19 wt% Fe; Alloy 2 similar to Stellite 6, 64 wt% Co, 24 wt% Cr, 4.2 wt% W, 2,3 wt% and Alloy 3 similar to Tribaloy – T400, 56 wt% Co, 8.5 wt% Cr, 29 wt% Mo, 3.3 wt% Si. These alloys are being used for manufacturing guides for hot rolling seamless steel pipes. Alloy 2 and Alloy 3 are being tested as wear segments used inside a 2nd generation ethanol reactor. Tests were performed using three 0.1 g/cm3 slurries composed by SiO2, Al2O3, and SiC particles, in a distilled water suspension. A load of 0.3 N was applied, the rotational speed was 20 rpm and the total sliding distance 48 m. Analysis of the alloys' tribosurfaces – by Optical Microscopy, Scanning Electron Microscopy and Contact Stylus Profilometry – showed abrasive size, shape and hardness may influence wear coefficients significantly. Tests performed with SiC and Al2O3 slurries resulted in greater wear rates than those with SiO2 slurry. Alloy 1 showed the greatest wear coefficient, in comparison with the other two experimental alloys, due to the absence of hard second phase precipitates in its microstructure. The variation of the wear coefficients as a function of abrasive hardness (Ha) and the compound alloy hardness (Hs) showed a linear correlation (R2 = 0.73). Two-body abrasion (grooving wear) was the dominant wear micro-mechanism observed for all tests. Alloy 2, containing Laves phase showed a transition from ductile to brittle wear mechanism when tested with alumina slurries. The SiC slurry gave the highest worn volume among the three tested slurries.

The magnetic properties of seamless steel pipe: Willcock, S.N.M.; Tanner,B.K. Journal of Magnetism and Magnetic Materials, Vol. 66, No. 1, pp. 153–157 (Mar. 1987)

The magnetic properties of seamless steel pipe: Willcock, S.N.M.; Tanner,B.K. Journal of Magnetism and Magnetic Materials, Vol. 66, No. 1, pp. 153–157 (Mar. 1987)

Experimental Studies of Ratcheting of Pressurized Pipe

In these studies, both dynamic and static tests were conducted on pressurized pipe. Dynamic tests were run on 1 in. Schedule 40 and Schedule 10 seamless 304 stainless steel pipe. Welded 1 in. Schedule 40 304 stainless steel pipe and seamless carbon steel (ASTM A106) pipe were tested statically. Internal pressures varied from 1000 psi to 3000 psi. In these tests, axial bending stresses from either inertial loads or static loads were superposed on to the initial pressure stresses. Strain gages were used to measure the cyclic strains on the outer walls of the pipe. Measurements indicated that ratcheting occurred primarily in the hoop direction and varied from a maximum at the top and bottom of the pipe that had the highest bending stresses to zero at the neutral axis. Though ratcheting occurred primarily in the hoop direction, some ratcheting in the axial direction was observed in 304 stainless steel pipe in both static and dynamic tests. Axial ratcheting was insignificant in the carbon steel pipe. Data obtained from these tests are presented. Measured ratcheting strains are compared to approximations of Beaney, Edmunds and Beer and to finite element computations.

シームレスクラッド鋼管の製造法および周溶接法の開発

シームレスクラッド鋼管の製造法および周溶接法の開発

The magnetic properties of seamless steel pipe: 36615 Willcock, S.N.M.; Tanner, B.K. Journal of Magnetism and Magnetic Materials, Vol. 66, No. 1, pp. 153–157 (Mar. 1987)

The magnetic properties of seamless steel pipe: 36615 Willcock, S.N.M.; Tanner, B.K. Journal of Magnetism and Magnetic Materials, Vol. 66, No. 1, pp. 153–157 (Mar. 1987)

Drive Roller Shoes in Helical Rolling Mill for Seamless Steel Pipes

Drive Roller Shoes in Helical Rolling Mill for Seamless Steel Pipes

Flexible Manufacturing Process in Cold Drawing Plant of Seamless Steel Tube

We have installed an FMS(Flexible Manufactruring System) in the cold drawing plant for manufacturing high-grade seamless steel tubes and pipe such as those used for oil fields, boilers and chemical plants, etc.Before the installation of FMS, we depended on the conventional batch processes and multi-kind small-quantity production method.Our FMS consists of automated material transfer, an automatic-warehouse, an advanced technique for production and a new production control system. The new production control system is composed of a business computer and a process computer which consists of decentralized micro-computers. Their main functions are planning the production schedule, tracking the production goods material flow control and automatic preset controls, etc. This operation control system the process computer is the most important function in FMS. The primary aim of this report is to describe the process computer system and the individual functions of the micro-computers.

The magnetic properties of seamless steel pipe

The magnetic and metallurgical properties of seamless pipe steel have been investigated as a function of position around the pipe circumference. No changes in magnetic properties were found to be associated with the four cycle spiral variations in pipe wall thickness introduced during forging. A weaker single cycle thickness variation was accompanied by a change both in magnetic properties and pearlite fraction. The coercive field predicted from an empirical relationship between grain size and ferrite and pearlite fractions was found to be in excellent agreement with that measured experimentally.

継目無鋼管のせん孔圧延におけるプラグの温度と表層挙動

継目無鋼管のせん孔圧延におけるプラグの温度と表層挙動

Production of HSLA seamless steel pipes for offshore structures and line pipes by direct-quench and tempering.

Production of HSLA seamless steel pipes for offshore structures and line pipes by direct-quench and tempering.

電磁超音波による熱間継目無鋼管肉厚計の開発

電磁超音波による熱間継目無鋼管肉厚計の開発

Specification of steel for producing petroleum tube by extrusion

Seamless steel pipes for the petroleum industry are produced by a hot-extrusion process. Extrusion processing deforms the material in three dimensions with a very high deformation ratio. In one operation the deformation ratio may sometimes reach 100:1, higher than in any other hot-working process. During this process grains are heavily deformed and recrystallization will take place depending on the finishing temperature; grain growth may sometimes be expected. Full-scale plant experiments have been carried out with various low-alloy carbon steels in a horizontal Davy-Loewy press of 30 MN capacity to produce tubes of 108mm i.d. and 5·6mm wall thickness. To analyse all aspects of the hot-extrusion process, mechanical properties have been determined in accordance with API specifications. Effects of sulphide and oxide inclusions on the workability and final properties of the material have been investigated. The effects ofprocess parameters on yield strength and grain size have been determined. Recommendations have been made to the manufacturer on selecting the suitable composition and cleanness, and on setting the parameters.

Pullout Tests of Piles in Sand

Three pullout tests on two instrumented 24-in. -diameter, steel-pipe piles were performed in a deep sand deposit at Mustang Island, Tex., to determine the tension capacity of a pile and to assess the effects of lateral loading on pullout resistance. Test equipment and procedures are described and results of strain data and load vs pile-top movement are presented. Skin friction parameters are determined from these results. Introduction Pullout tests on open-steel pipe piles in sand were run at Pullout tests on open-steel pipe piles in sand were run at the Shell Oil Co. Tank Battery on Mustang Island, Tex. The map in Fig. 1 indicates the test site. About 5 ft of fill was excavated at the site so that the water table would be at ground surface. Two instrumented test piles were driven and pullout tests were performed before and after lateral loading. Test Equipment and Test Piles Test Setup and Test Piles The test setup and test piles are shown in Fig. 2. Two reaction beams, one on each side of the test pile, rested on timber mats. Two hydraulic jacks with pumping units and pressure gauges rested on the reaction beams. A 10-ft pressure gauges rested on the reaction beams. A 10-ft section of 24-in.-diameter pile was specially made and welded to the top of the test pile. Two small-diameter piles were driven to support deflection gauges used to piles were driven to support deflection gauges used to measure movement of the pile top. Cables from deflection and strain gauges were run from the pile to the instrumentation system housed in a van parked beside the excavated area. Two test piles were manufactured from seamless steel pipe (ASTM A-53, Grade B) with 24-in. OD. The wall pipe (ASTM A-53, Grade B) with 24-in. OD. The wall was 3/8-in. thick and weighed 94.6 lb/ft. The piles were composed of a 10-ft loading section, a 32-ft instrumented section, and 38-ft anchor section (Fig. 2). The instrumented section was sealed off by diaphragms at the top and bottom of the section to prevent moisture from damaging the strain gauges. Wires from these gauges were passed through pressure-packing glands in the diaphragm at the top of the instrumented section. Each pile had 40 strain gauges - 34 active and 6 unstrained dummies. The 120-ohm strain gauges were 0.50- x 0.50-in. metal foil. Strain-gauge spacing in the 32-ft section is indicated in Fig. 2. Both test piles were driven with a Delmag-12 diesel hammer. The 38-ft open-ended, uninstrumented section was driven until its top was about 3 ft above the soil surface. Next, the soil plug inside the section was augered out completely to keep it from driving against the diaphragm in the bottom of the 32-ft instrumented section. After welding the 32-ft section to the 38-ft section, driving was resumed and the pile was driven to grade, with the pile flange approximately I ft above the soil surface. The pile was embedded 69 ft. Measurement of Load, Strain, and Deflection During the pullout tests, readings were taken of the applied load, the deflection of the top of the pile, and the axial strain along the pile. The applied load was obtained by reading bourdon-tube pressure gauges that measured the hydraulic pressure in the jacks. The pile deflection was obtained from dial indicators and by use of lineardisplacement transducers. Output from the displacement transducers and from strain gauges was recorded with a digital recording system. JPT P. 343

On properties of titanium weldrawn tube

Titanium tubing has increased its importance in chemical industries because of its excellent corrosion resistance.At the present time, titanium tubes are manufactured primarily by the following two processes in the authors' company.1 Hot extruding, which is usually followed by cold drawing.2 Rolling sheet strip into tube form, and shielded are welding with or without suhsequent cold drawing.The titanium tube manufactured by means of welding and cold drawing, is called “weldrawn tube” representing high quality.The authors prepared the KS-50 titanium (Commercially high purity grade) weldrawn tubes, for the welding of which an inert gas chamber welding apparatus wat used.This report involves the investigations of these weldrawn tube on their mechanical properties and microstructure of cross section.The results are summarized as follows:1 Dimensional test of titanium weldrawn tube indicated that wall-thickness and concentricity could be maintained within very narrow limits. Surface appearance was also excellent.Microstructure as well as hardness of the tube cross section became uniform in welded and unwelded zones by cold drawing and annealing.2 In practical tests, titanium weldrawn tube showed that its values exceeded those of JIS specification on seamless and electric welded steel pipes.3 The weldrawn tube of 23OD×1.65t withstood hydraulic pressure of 600kg/cm2 G and the permanent strain of the tube at the test was 5×10-3 in circumference.4 Titanium clad steel pipe was manufactured by the authors as one of applications of titanium weldrawn tube.

Load-Deflection Relations for Large Plain, Corrugated, and Creased Pipe Bends

Abstract This paper presents the results of tests made on 10-in. and 14-in. seamless steel pipe loaded in the same manner as the simple cases shown on pages 526 to 529, “Piping Handbook,” by Walker and Crocker. Comparison has been made between calculated deflections and the results of tests in the six cases for a plain pipe bend. The relation between the results of tests on corrugated and creased pipe bends and the calculated results for plain pipe bends of the same dimensions are shown. Such calculations are included as are necessary to show the method of analysis by which the load-deflection relations of a plain quarter-bend and its tangents are determined.