Stainless Steel-carbon Steel Research Articles

Equivalent Properties of Transition Layer Based on Element Distribution in Laser Bending of 304 Stainless Steel/Q235 Carbon Steel Laminated Plate

Compared with the single-component metal plate, there is a special transition layer on the joint interface between two kinds of materials in the stainless steel-carbon steel laminated plate (SCLP). In order to describe the finite element model of laser bending accurately, it is of great significance to determine material properties of the transition layer. Based on the element distribution, an equivalent method is adopted to calculate thermal conductivity, thermal expansion coefficient, elastic modulus, density, Poisson’s ratio, and specific heat capacity of transition layer. The electron probe experiments show that the transition layer is formed by interfacial element diffusion with thickness of 7 μm. Besides, the volume fraction of stainless steel (46.63%) and carbon steel (53.37%) in the transition layer is tested by energy dispersive spectrometer, respectively. Through the equivalent method, a laser bending model of SCLP is simulated by ANSYS software to predict the bending angle under different parameters. The experimental verification shows that the maximum of bending angle errors is 3.74%, which is lower than the maximum 4.93% of errors calculated by the mean value method. The analysis verifies that the laser bending model is feasible and contributes to improving the accuracy of modeling SCLP in the laser bending process.

Friction stir lap welding of stainless steel and plain carbon steel to enhance corrosion properties

Friction stir lap welding-a precursor to the friction stir cladding- stainless steel on plain carbon steel was attempted. Refined microstructure with fully recrystallized austenitic grains with ∼3 μm grain size and intermixing with base steel sample resulted in defect free lap weld. The pin affected region of the base carbon steel resulted in grain refinement from initial grain size of 8 μm to 2 μm. The microhardness values across the joint line showed stable values of ∼250 HV on the stainless steel side and ∼200 HV on the carbon steel side. Lap shear tests showed consistent load bearing capacity of ∼7 kN for the stainless steel-carbon steel joint. The weld between stainless steel and carbon steel showed 100% joint efficiency with similar yield strength of ∼440 MPa as the base steel sample and with an increase in ultimate tensile strength to ∼600 MPa as compared to ∼500 MPa for the base steel sample. The failure of clad tensile samples occurred in the base steel plate. Corrosion characterization of the clad surface was conducted in 3.5 wt.% sodium chloride solution. The potentiodynamic polarization showed positive corrosion potentials with a large passive range of ∼500 mV for the clad surface and a decrease in corrosion rates by more than an order as compared to the base steel sample. The friction stir lap welded stainless showed similar electrochemical properties as of the base stainless steel sheet.

Prediction of a High Temperature Bonding Condition at the Interface for the Hot-Rolled Stainless Steel Clad Plate on Rolling

The stainless steel-carbon steel clad plate was investigated using the theoretical analysis of various factors influencing the high-temperature interfacial bonding during its rolling. Phenomenological prediction analysis model of interfacial bonding strength at high temperature which considers the vacuum depth, rolling temperature, and rolling reduction, was established. The specific thermal simulation experiment was designed. The bonding strengths of carbon steel and stainless steel at 1000~1200°C and compression degree of 10~30% were measured by a Gleeble 3500 thermal simulator, as a result, the interfacial bonding ratio was obtained. The results show that the bonding ratio is 0.5–0.65 at the experimental temperature and compression degree. The numerical simulation method was used to analyze the influence of the compression degree of the first pass for a 2000 × 1500 × 100 mm stainless steel clad plate under the interfacial bonding conditions. The simulation results show that the optimum compression degree of the first pass is 15–20% at the rolling temperature of 1200°C.

The Corrosion Behavior of 17-4 Stainless Steel in a Stainless Steel-Carbon Steel Galvanic Couple

The Corrosion Behavior of 17-4 Stainless Steel in a Stainless Steel-Carbon Steel Galvanic Couple

Thermogalvanic Currents in Steel Reinforced Concrete

The thermogalvanic currents between nominally identical segments in a reinforced concrete beam were investigated. Temperature gradients induce galvanic currents that exhibit a 30°C critical point. The character of the hot electrode side changes from anodic to cathodic when the temperature rises above that pivot point. Parallel tests performed in solution using carbon steel-stainless steel galvanic couples also revealed that 30°C is a critical temperature. In NaOH solution the carbon steel behaves cathodically with respect to stainless steel but only for T<30°C. In Ca(OH)2 solution containing chlorides the carbon steel consistently behaves anodically while the degree of thermogalvanic current exhibits a pronounced temperature dependence.

Mechanical Properties Comparison of Stainless Steel 304L and Carbon Steel BS1387 Prior to Orbital Welding

Dissimilar metal joint (DMJ) is one of many joining methods for welding processes which is common in the power plant, chemical and petrochemical industries. Stainless steel pipe and carbon steel pipe are the most widely used in this technique. In order to perform DMJ to these metals, it is important to understand the mechanical properties of both base materials. In this study, the characterizations of stainless steel (SS) 304L and carbon steel (CS) BS1387 were made. The SS 304L and CS BS1387 were cut out from pipes according to ASTM E 8M-04, before their tensile and microhardness properties were measured and evaluated. The results show that the SS 304L has better mechanical properties compared to the CS BS1387 pipe in terms of tensile strength and hardness. Due to the higher mechanical properties, SS 304L was selected to conduct higher temperature water, while CS BS1387 was selected to conduct room temperature water.

Evaluation of Bond Quality for Stainless Steel-Carbon Steel Friction Surfaced Deposits

Friction surfacing is one of the advanced techniques in the family of friction welding processes and is used for deposition of desired material on substrate of interest. These deposits are of solid phase bonding. No external heat source is required and heat is developed by friction. It is suitable for critical applications such as wear resistance, corrosion resistance and also for challenging dissimilar applications.In this work, friction surfacing was carried out by using Stainless steel as mechatrode and Low carbon steel as substrate. This paper is an attempt to give review details of the variants of friction surfacing techniques, bonding mechanism, factors selection of process parameters to apply on different combinations of materials and confirming the same with experimental test results. Effect of process parameters on the responses like width, height, surface roughness, tensile strength shear strength and ratio of tensile strength and shear strength are discussed in details. Testing of deposits for quality evaluation also carried out such as visual inspection, adhesion test, and microstructure and hardness distribution to find potential industrial applications. For the particular combination, the influence of the factors which are effecting above responses was discussed and regression equations were arrived at based on the design of the experiments approach. It is hoped that this research report will be of immense useful for all professional who would like to exploit this process development and identifying the useful applications.

不锈钢碳钢层合板激光弯折区增厚现象研究

不锈钢碳钢层合板激光弯折区增厚现象研究

考虑结合面的不锈钢碳钢层合板脉冲激光弯曲数值模拟

考虑结合面的不锈钢碳钢层合板脉冲激光弯曲数值模拟

激光熔覆不锈钢-碳钢层合板的材料性能

激光熔覆不锈钢-碳钢层合板的材料性能

不锈钢碳钢层合板激光弯折区的热传导特性

不锈钢碳钢层合板激光弯折区的热传导特性

不锈钢碳钢层合板激光弯曲试验研究

不锈钢碳钢层合板激光弯曲试验研究

Synergy of erosion and galvanic effects of dissimilar steel welding: Field failure analysis case study and laboratory test results

Welding austenitic stainless steels to carbon and low alloy steels are widely practiced in the process and construction industries. Their potential failures are underrated and underreported. In this research, erosion accelerated corrosion of a carbon steel-stainless steel galvanic couple was simulated to mimic the field failure analysis. The weight-loss of a metal during erosion–corrosion is caused by both galvanic corrosion component and erosion component. Furthermore, the results show that the percentage of corrosive weight-loss of the total weight-loss increases with the increasing cathode/anode area ratio, indicating the accelerating corrosion of carbon steel under the large cathode-small anode geometry.

Galvanic Corrosion of a Carbon Steel-Stainless Steel Couple in Sulfide Solutions

The galvanic corrosion behavior of carbon steel-stainless steel couples with various cathode/anode area ratios was investigated in S2−-containing solutions, which were in equilibrium with air, by electrochemical measurements, immersion test, and surface characterization. It is found that the galvanic corrosion effect on carbon steel anode increases with the cathode/anode area ratios, and decreases with the increasing concentration of S2− in the solution. A layer of sulfide film is formed on carbon steel surface, which protects it from corrosion. When the cathode/anode area ratio is 1:1, the potentiodynamic polarization curve measurement and the weight-loss determination give the identical measurement of the galvanic corrosion effect. With the increase of the cathode/anode area ratio, the electrochemical method may not be accurate to determine the galvanic effect. The anodic dissolution current density of carbon steel cannot be approximated simply with the galvanic current density.

Failure of weld joints between carbon steel pipe and 304 stainless steel elbows

A number of weld joints between carbon steel (CS) pipe and type 304 stainless steel (SS) elbows constituting a gas piping system of a petrochemical unit developed cracks after a relatively short period of usage, resulting in leakage. The gas flowing through the pipe, was hydrogen rich at a temperature of 45 °C and a pressure of 16 kg/cm 2. Light optical metallography and scanning electron microscopy, combined with energy dispersive X-ray spectroscopy, inductively coupled plasma and microhardness testing were used to determine the most probable cause of failure. Analysis showed that the cracks originated at the interface between the CS pipe and the SS root weld. A narrow band between the CS pipe and SS weld exhibited a hardness of Rockwell C 60 suggesting the formation of martensite due to C segregation at welding temperature and subsequent quenching during cooling. The ferritic region of CS adjacent to the weld was decarburized and was devoid of pearlite; corroborating C diffusion. The weld region was diluted comprising mainly of Fe with small amounts of Cr and Ni. Cracking is thought to have initiated at the hardened region. However, the failure might have been aided by hydrogen rich medium and soft C-depleted ferrite region.

Variations of Strain Distribution and Plastic Zone at Fatigue Crack Tip Crossing the Interface of Two-Layered Low Carbon Steel-Stainless Steel Composite Plates

Moiré fringe multiplication method using the interference of diffracted laser beams was used to evaluate the strain distribution at the fatigue crack tip which was crossing the interface of two-layered composite plates composed of low carbon steel and ferritic or austenitic stainless steel. All the tests were carried out under pulsating tension with the stress ratio R≅0. The area Ω surrounded by equi-strain loci of εy, the strain component in loading direction, was obtained from the measurements, and its variation was discussed with relation to the complicated crack propagation behavior near the interface.It was concluded that the variation of Ω could be understood by considering both of the distribution of residual stress in the constituent materials and the difference in yield strength between two materials, and that a modified stress intensity factor, which was obtained by correcting the ordinary stress intensity factor with consideration of the variation of Ω, was a much better parameter controlling the crack growth rate near the interface.

Fatigue Crack Propagation Behavior of Two-layered Low Carbon Steel-stainless Steel Composite Plates

Observation and analysis were made on the effect of thermally induced residual stress on propagation and opening behavior of fatigue cracks in multilayered composite plates which were composed of low carbon steel and ferritic or austenitic stainless steel. It was observed that the crack propagation behavior in the composite plates was quite different from that in the monolithic plates, when the crack growth rates were plotted against kmax·But, when those were plotted against ΔKeff, the data points of the composite plates came close to those of the monolithic plates, although there were some scatters. This suggested that the residual stress had a large influence on the crack opening behavior in the composite plates. Therefore, by calculating the actual stress intensity factor K'max for the composite plates based on an initial distribution of residual stresses, their crack opening behavior was estimated by using k'max and the crack opening behavior of monolithic plates. The estimated trends showed a fairly good agreement with those of the observed results.

Anticorrosion protection of fermentation apparatus

ne amounted to 0.2-0.4 mm per year, which, according to the standard classification, corresponds to a low resistance of the material (group IV, 6 points). Experiments and the practical use of steel fermenters have shown that with the lapse of time in the course of the working of the apparatus corrosion slows down because of the formation on the surfaces in contact with the culture liquid of protective passivating films. In a study of a film about 2 mm thick taken from the walls of an industrial fermenter for the production of penicillin, it was found to have a layer structure [2]. This film, which had deposited after 1.5 years of working, consisted mainly of calcium carbonate cemented by caramelized sugars, pectins, etc. The film formed after some years on the working surface of a steel fermenter for the production of streptomycin contained about 74% of iron oxide and approximately 18% of organic substances [3]. The formation of passivating films is of great importance both from the point of view of the anticorrosion protection of the metal and for the normal conditions of growth of the culture and the production of the antibiotic, since an excess of iron in the medium due to corrosion has an adverse effect on biosynthesis [4-6]. This is the case particularly when fats with high iodine numbers forming unsaturared fatty acids are used as foam suppressors, since iron ions stimulate the formation of peroxide compounds which are toxic to the producing agent [7]. A marked fall in the productivity of fermentation in the absence of a protective film on a steel surface in contact with the culture liquid has been observed in experiments [I]. The antibiotic activity of the liquid fell in the case of penicillin by a factor of 1.5, for streptomycin by almost 2, and in the case of ehlorotetracyeli ne almost completely. When a protective film is present there is no appreciable fall in activity, and this makes it possible to use carbon steel fermenters. However, this film does not prevent corrosion completely but only retards it. Also important is the fact that the protective film is not uniform in the different parts of the apparatus. Its formation and the strength of its adherence to the metal surface are affected by the nature of the flows of aerated liquid created by the mixer, the temperature stresses, and other factors. In some parts of the apparatus the film is particularly strongly subjected to erosion, sharp changes in temperature on sterilization and cooling, mechanical effects in the cleansing of the fermenter, etc. In view of this, such parts of steel apparatus as coils, stirrers, and stairs are put out of commission by corrosion in the course of a few years' work [8]. As a result of the incomplete adhesion of the film to the surface of the metal and its local lamination, etc., so-called pitting corrosion takes place in various parts of the apparatus, leading to the formation below the film of deep (up to 8 ram) cavities and bubbles, since the thickness of the wall of the body of industrial fermenters with a capacity of 50 m 3 is 12-14 ram, such corrosion represents a threat to the mechanical strength of the apparatus when pressure is created in it. These reasons explain the tendency observed in the world practice of the industrial production of antibiotics to make fermenters from alloy stainless steels or from a bimetal (carbon steel-stainless steel). Such apparatus is suitable for working and has a long life, but its manufacture is affected by the shortage of stainless steel and is associated with large capital charges, which, in a number of cases, make it impracticable (for example, in the organization of the production of fodder antibiotics in agricultural undertakings) [9]. For these cases it is necessary to find an anticorrosion protection of the internal surface of steel fermenters by means of special coatings.