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Baosteel Technical Research
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2008-02

1.A review of Baosteel's development of steel for oil and natural gas
Yin Guanghong
Steel Tube Division , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
Abstract: The development of oil and natural gas steel products at Baosteel over the past two decades is reviewed in this paper . After years of researching and developing steel products that are used in the energy industry such as drilling , exploitation , collection , transportation , and the storage of oil and natural gas , the system of composition and manufacturing techniques for Baosteel's oil and natural gas steel products have been established . The oil and natural gas steel products of Baosteel consist of two major categories : the oil country tubular goods ( OCTG ) used underground , and the pipes used for pipeline construction on the ground . Currently , the product quality has maintained stability , and the related products have been extensively used worldwide for the exploration and transportation of oil and natural gas .
Key words : petroleum ; natural gas ; drill pipe ; tubing ; casing ; OCTG

2.XPS analysis of passive film formed on the G3 nickel-base alloy tubing under corrosive conditions
Zhang Zhonghua1, Zhang Chunxia1, Yang Jianqiang1 and Chen Changfengng2
1) Steel Pipe Division , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
2) Department of Material Science and Technology , China University of Petroleum , Beijing 102249 , China
Abstract: In the present study , the passive film formed on the G3 nickel-base alloy tubing under corrosive conditions including H2S , CO2 , and CI-at 130 C and 205C is studied with X-ray photoelectron spectroscopy ( XPS ) . The results reveal that the passive film formed at 205C consists of Cr , Ni , Fe ,S and O elements and is over 470 nm in thickness . The passive film can be divided into three layers , the outer-layer is composed of NiS2 and Cr2S3 , the intermediate-layer of Cr ( OH ) 3 , Ni ( OH ) 2 , NiS2 , Cr2S3 and a small quantity of NiO and Cr2O3 , and the inner-layer of NiO , Cr2O3 , and alloy elements . Due to the invasion of S2-into the passive film and the decrease of the content of chromium oxide in the film , the corrosion resistance of the G3 alloy in the sour environment at 205C is weakened .
Key words: XPS ; G3 nickel-base alloy ; passive film

3.The development and application of premium thread connection tubing and casing products from Baosteel
Wang Li1 and Zhao Yong an2
1) Steel Tubing Plant , Baosteel Branch , Baoshan Iron & Steel Co . , Ltd . , Shanghai 200941 , China
2) Steel Pipe Division , Reserarch Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
Abstract: Premium thread connection tubing and casing products are non-API products that are used in severe oil field conditions , such as deep wells ,ultra deep wells, high pressure gas wells, horizontal wells and steam injection wells , etc . In order to meet the requirements of oilfields for premium thread connection oil country tubular goods ( OCTG ) , Baosteel developed its own series of premium thread connection tubing and casing products that are protected by intellectual property rights. This study introduces the process of developing the premium thread connection tubing and casing products, their characteristics, and their actual application in oil fields. It hopes to give customers a better understanding of Premium thread connection tubing and casing products from Baosteel.
Key words : premium thread connection ; non-API products ; OCTG

4.The development of super-high collapse resistant casing
Tian Qingchao and Dong Xiaoming
Steel Pipe Division , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
Abstract: Super-high collapse resistant casings were developed by using Ti , Nb and V microalloyed CrMo steel and cross rolling techniques . A transmission electron microscope ( TEM ) and X-ray diffractometer were used to observe the characteristics of the microstructure . It was found that the ( 111 ) texture and the nano-scale precipitates distribute in a way that is beneficial to the collapse resistance , and the collapse strength of the prepared casing had a measurement , which was approximately 60 % higher than the API standard value . A design concept to attain super-high collapse resistance is proposed based on the texture design and microstructure control .
Key words: super-high collapse resistance casing ; texture ; precipitation hardening

5.The extraction of slag in seawater and its influence on the growth of phytoplankton
Dong Xiaodan
Economics & Management Research Institute , Baosteel Group Corporation , Shanghai 200122 , China
Abstract : Initial research was carried out on the extraction and absorption of metal ions in seawater slag and their influence on oceanic phytoplankton . It was discovered that the pH in a steel slag solution that had a certain concentration ( 1.67 g/L ) increased as the time for oscillation ( four days ) was extended . The four elements of Zn , Mn , AI and Cu all displayed the basic signs of extraction , while Fe , Cr , As , Pd , Hg , Se and Cd all displayed the basic signs of absorption . Although there were some changes in the content of Ca and Mg , the changes were not very evident during the time of the experiment . When the time for oscillation was further extended ( up to 16d ) , the change in the solution 's level of pH was small , but the concentration of metal ions largely decreased . In natural coastal seawater , the steel slag showed no ability to promote the growth of Heterosigma akashiwo ( H akashiwo ) ; while in nutritious coastal seawater , steel slag with a concentration of less than 392 mg / L could stimulate the growth of H akashiwo . However , the growth of H akashiwo was inhibited when the concentration was more than 488 mg / L . In nutritious coastal seawater without microelements , steel slag with a concentration of less than 124 mg / L obviously stimulated the growth of H akashiwo . In ocean water , the growth of H akashiwo was accelerated when the concentration of steel slag was less than 250 mg / L and the concentration was increased . However , growth simulation was decreased with further increases to the concentration of steel slag . Therefore , it can be said that slag has an optimal concentration for the growth of H akashiwo .
Key words: steel slag : CO2:extraction : greenhouse effect : Heterosigma akashiwo : seawater

6.Practice of improving the hot blast temperature for the 2500m3 BF
Li Yiwei , Shi Jian 'en , Bao Lei and Wang Yi
Ironmaking Plant , Stainless Steel Branch , Baoshan Iron & Steel Co . , Ltd . , Shanghai 200431 , China
Abstract: A high blast temperature is an effective measure that improves pulverized coal injection ( PCI ) and energy consumption , decreases the cost of blast furnaces ( BF ) . Apart from using technology such as the increased vault temperature of the hot-blast stove , the increased temperature of the waste gas , the preheating of combustion air and gas , and fully closed mixed air valves , other measures , such as using an oxygen-enriched blast stove , burning high heating value converter gas , increasing the number of stove changes to reduce the time needed for stove blasts , were taken to increase the blast temperature of the 2500m3 BF in recent years . The blast temperature of the 2500m3 BF was continuously increased in these years . The monthly average temperature of the 25OOm3 BF reached 1158C , with the highest blast temperature reaching 1195C in 2006 . This technique of increased blast temperatures has reached an advanced level in China .
Key words : hot blast stove ; high blast temperature ; oxygen-enriched stove ; converter gas

7.Technical analysis of producing low Ni pig iron with laterite in a blast furnace
Zhang YouPing , Zhou Yusheng and Li Zhaoyi
Ironmaking Division , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
Abstract : As nickel is mainly used to produce stainless steel , the demand for nickel is increasing . With the steady decline of nickel sulfide ore reserves , laterite will become the main source of nickel . In regards to China 's current blast furnace method of producing pig low Ni iron with laterite , this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite . The study aims to provide a reference for the better use of laterite in China .
Key words : laterite ; blast furnace ; pig iron with a low Ni content

8.High temperature mechanical properties of low carbon silicon-bearing steel by twin-roll strip casting
Zhang Ting1,Wu Jianchun2 ,Yu Yan2 and Fang Yuan2
1) School of Material Science and Engineering , Southeast University , Nanjing 211189 , Jiangsu , China ;        
2) Advanced Technology Division, Baosteel Research Institute, Baoshan Iron & Steel Co. Ltd., Shanghai 201900, China
Abstract : The tensile equipment of the advanced confocal scanning laser microscope ( CSLM ) was used to research the high temperature mechanical properties of low carbon silicon-bearing steel by twin-roll strip casting . The results show that , at the strain rate of 0.0005s-1, the strip clearly shows signs of brittleness at around 600 C and its plasticity falls considerably between 750C and 600C . This is because during the transformation from austenite to ferrite, the low strength ferrite at the austenite grain boundaries greatly reduces the steel 's high temperature plasticity . The subsequent strip coiling process should be controlled at less than the brittle temperature of approximately 600C ,so cracks at the coiling stage can be prevented .
Key words : strip casting ; high temperature mechanical properties ; CSLM ; in-situ observation ; brittle fracture

9.The effect of V-Nb on the growth of austenite grains in 17 CrNiMo6 gear steel
Zhao Yaping1,Wang Maoqiu2 and Yuan Jiguo1
1)Special Steel Branch , Baoshan Iron & Steel Co . , Ltd . , Shanghai 200940 , China
2)Central Iron and Steel Research Institute , Beijing 100081 , China
Abstract : This study researches the effect of V-Nb on the growth of austenite grains in 17CrNiMo6 carburized gear steel . Results show that the carbonitride in V and Nb acts as second-phase particles in the steel , which can be used to block the migration of grain boundaries and the thinning of the austenite grains . This causes the crystals in the V-Nb microalloy 17 CrNiMo6 steel to coarsen and the temperature to rise , thus reducing the cost of the carbonization that follows processing on the gears .
Key words : V-Nb microalloy ; 17 CrNiMo6 steel ; austenite grain ; pinning effect

10.InfluenCe of loCal tensile loading on the distribution of welding residual stress fields in cylinder shells
Pan Hua and Lei Ming
Auto Steel Division , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 201900 , China
Abstract : The feasibility of reducing the welding residual stress through local tensile loading is verified using the finite element method ( FEM ) . The mechanism and effect of reducing stress during and after welding are compared . The results show that the effect of the former is better than that of the latter . Applying an external tension load of 200 MPa after welding , the maximum residual stress drops down from 235 MPa to about 90 MPa , moreover , it decreases to 3OMPa when an external tension load of 200 MPa is applied during welding .
Key words : welding ; residual stress ; FEM ; mechanical tensioning

11.Surface segregation of copper in antibacterial ferritic stainless steel
Zhang Zhixia , Lin Gang and Jiang Laizhu
Technology Center for Stainless Steel , Baosteel Research Institute , Baoshan Iron & Steel Co . , Ltd . , Shanghai 200431 , China            
Abstract : By using auger electron spectroscopy ( AES ) and diffusion theory to analyze the surface segregation of copper in antibacterial ferritic stainless steel , establishing a diffusion model , and calculating the activation energy of diffusion of the copper in ferrite , the affect of surface segregation on the antibacterial capabilities were researched . The results show that the concentration of the copper surface at 973 K and 1 073 K could be expressed asln ,        with the parameters relating to the concentration of the diffusion layer , the coefficient of diffusion , the length of diffusion , the latent heat of evaporation and the latent heat of fusion . The activation energy of diffusion of copper in ferrite is approximately  221.688 kJ/mol. The antibacterial property of the steel is improved as the surface segregation of the copper is increased . At 1073K for 60 min , the concentration of the surface copper is over three times higher than the basic concentration . The antibacterial property of the stainless steel can reach approximately 99.9% .
Key words : ferritic antibacterial stainless steel ; copper surface segregation ; diffusion ; AES

12.Research on the AOD molten iron manufacture of ferritic Stainless Steel
Chi Hebing , Shao Shijie and Li Dong gang
Steelmaking Plant , Stainless Steel Branch , Baoshan Iron & Steel Co . , Ltd . , Shanghai 200431 , China
Abstract : Based on the existing technology and equipment for stainless steel production , the smelting process of ferritic stainless steel in the argon-oxygen decarburization ( AOD ) furnace using blast furnace ( BF ) molten iron ( after dephosphorization ) and ferrochrome alloy is studied and discussed . In the new process , phosphorus and other harmful elements are reduced to a lower level ( P≤0.020 % ) when smelting ferritic stainless steel . With this process , both production flexibility and efficiency are enhanced . As no electric furnace is used in the smelting , the production cost is lowered with a great deal of electric power saved , while the total yield of chromium is increased .
Key words : AOD ; molten iron ; ferritic stainless steel