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Article
Publication date: 16 August 2011

Mumin Sahin and Ceyhun Sevil

The aim is to provide detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels.

Abstract

Purpose

The aim is to provide detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels.

Design/methodology/approach

Austenitic‐stainless steel was the material chosen for the present study. Ion nitriding process was applied to fatigue and tensile samples prepared by machining. Process temperature was 550°C and treatment time period 24 and 60 h. Then, tensile, fatigue, notch‐impact, hardness tests were applied and metallographic examinations were performed.

Findings

High temperature and longer treatment by ion nitriding decreased fatigue and tensile strengths together with notch‐impact toughness. Scanning electron microscopy and energy dispersive X‐ray spectroscopy analysis revealed formation of nitrides on the sample surfaces. Surface hardness increased with an increase in process time due to diffusion of nitrogen during ion nitriding.

Research limitations/implications

It would be interesting to search the different temperature and time intervals of the ion nitriding. It could be a good idea if future work could be concentrated on ion nitriding on welded stainless steels.

Practical implications

Surfaces of mechanical parts are exposed to higher stress and abrasive forces compared to inside mechanical parts during the time period that mechanical components carry out their expected functions. When stresses and forces exceed the surface strength limit of the material, cracks begin to form at the material surface leading to abrasion and corrosion. Therefore, surface strength of materials needs to be increased to provide a longer service life. Ion (plasma) nitriding is a possible remedy for surface wear.

Originality/value

The main value of this paper is to contribute and fulfil the detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels that are being studied so far in the literature.

Details

Industrial Lubrication and Tribology, vol. 63 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 30 May 2019

Pramod Kumar and Amar Nath Sinha

The present research work aims to study the effect of average beam power (laser process parameters) on the overlapping factor, depth of penetration (DOP), weld bead width…

Abstract

Purpose

The present research work aims to study the effect of average beam power (laser process parameters) on the overlapping factor, depth of penetration (DOP), weld bead width, fusion zone and heat affected zone (HAZ) in laser welding of 304L and st37 steel. Back side and top surface morphology of the welded joints have also been studied for varying average beam power.

Design/methodology/approach

Laser welding of austenitic stainless steel (304L) and carbon steel (st37) was carried out using Nd:YAG laser integrated with ABB IRB 1410 robot in pulse mode. The selection of laser process parameters was based on the specification of available laser welding machine. Dissimilar laser welding of 304L and st37 carbon steel for full depth of penetration have been performed, with varying average beam power (225-510W) and constant welding speed (5mm/s) and pulse width (5ms).

Findings

Recrystallized coarse grains were observed adjacent to the fusion zone and nucleated grains were seen away from the fusion zone towards carbon steel. Overlapping factor and HAZ width st37 side increases with increase in average beam power whereas top weld bead width increases first, attains maximum value and then subsequently decreases. Bottom weld bead width increases with increase in average beam power. The mechanical properties namely microhardness and tensile strength of the welded joints have been investigated with varying average beam power.

Originality/value

In the recent development of the automobile, power generation and petrochemical industries the application of dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) are gaining importance. Very limited work have been reported in pulsed Nd:YAG dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) for investigating the effect of laser process parameters on weld bead geometry, microstructural characterization and mechanical properties of the welded joint.

Details

World Journal of Engineering, vol. 16 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 February 2008

P. Sathiya, S. Aravindan and A. Noorul Haq

Friction welding is a solid state bonding process, where the joint between two metals has been established without melting the metal. The relative motion between the…

Abstract

Friction welding is a solid state bonding process, where the joint between two metals has been established without melting the metal. The relative motion between the faying surfaces (surfaces to be joined) under the application of pressure promotes surface interaction, friction and heat generation which subsequently results in joint formation. Stainless steel is an iron based alloy, contains various combinations of other elements to give desired characteristics, and found a wider range of applications in the areas such as petro‐chemical, fertilizer, automotive, food processing, cryogenic, nuclear and beverage sectors. In order to exploit the complete advantages of stainless steels, suitable joining techniques are highly demanded. The Friction welding is an easily integrated welding method of stainless steel, which considered as non‐weldable through fusion welding. Grain coarsening, creep failure and failure at heat‐affected zone are the major limitations of fusion welding of similar stainless steels. Friction welding eliminates such pitfalls. In the present work an attempt is made to investigate experimentally, the mechanical and metallurgical properties of friction welded joints, namely, austenitic stainless steel (AISI 304) and ferritic stainless steel (AISI 430). Evaluation of the characteristics of welded similar stainless steel joints are carried out through tensile test, hardness measurement and metallurgical investigations.

Details

Multidiscipline Modeling in Materials and Structures, vol. 4 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 February 2002

S. Sathiyanarayanan, C. Marikkannu, P. Bala Srinivasan and V. Muthupandi

Compares the corrosion behaviour of Ti6Al4V titanium alloy, a conventional duplex stainless steel (UNS 31803) and AISI 304 austenitic stainless steel in synthetic…

1055

Abstract

Compares the corrosion behaviour of Ti6Al4V titanium alloy, a conventional duplex stainless steel (UNS 31803) and AISI 304 austenitic stainless steel in synthetic biofluids using electrochemical techniques and comments on the suitability of DSS for use in biomedical applications. Finds that the general corrosion resistance of duplex stainless steels is slightly inferior to that of austenitic stainless steel and titanium alloy; duplex stainless steel does not show any sign of pitting when exposed to synthetic biofluids and exhibits excellent resistance to localised corrosion on par with that of titanium alloy. Concludes that duplex stainless steels are one of the best alternates to titanium alloys.

Details

Anti-Corrosion Methods and Materials, vol. 49 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 June 2005

Mumin Sahin

Aims to determine if friction welding is suitable for welding austenitic stainless steel (AISI 304)

Abstract

Purpose

Aims to determine if friction welding is suitable for welding austenitic stainless steel (AISI 304)

Design/methodology/approach

Uses an experimental continuous drive friction welding set‐up. Determined the strength, hardness and microstructure of the joined parts.

Findings

Finds that the joint strengths are 96 per cent of those of the base metals with no significant hardening.

Practical implications

Friction welding is an appropriate joining method for austenitic stainless steel (AISI 304).

Originality/value

Aids in understanding appropriate uses of friction welding for joining stainless steel.

Details

Assembly Automation, vol. 25 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 28 May 2021

Fan Bao, Kaiyu Zhang, Zhengrong Zhou, Wenli Zhang, Xiao Cai and Lin Zhang

The purpose of this paper is to demonstrate the effect of δ-ferrite on the susceptibility to hydrogen embrittlement of type 304 stainless steel in hydrogen gas environment.

Abstract

Purpose

The purpose of this paper is to demonstrate the effect of δ-ferrite on the susceptibility to hydrogen embrittlement of type 304 stainless steel in hydrogen gas environment.

Design/methodology/approach

The mechanical properties of as-received and solution-treated specimens were investigated by the test of tensile and fatigue crack growth (FCG) in 5 MPa argon and hydrogen.

Findings

The presence of δ-ferrite reduced the relative elongation and the relative reduction area (H2/Ar) of 304 stainless steel, indicating that δ-ferrite increased the susceptibility of hydrogen embrittlement in 304 stainless steel. Moreover, δ-ferrite promoted the fatigue crack initiation and propagation at the interface between δ-ferrite and austenite. The FCG tests were used to investigate the effect of δ-ferrite on the FCG rate in hydrogen gas environment, and it was found that δ-ferrite accelerated the FCG rate, which was attributed to rapid diffusion and accumulation of hydrogen around the fatigue crack tip through δ-ferrite in high-pressure hydrogen gas environment.

Originality/value

The dependence of the susceptibility to hydrogen embrittlement on δ-ferrite was first investigated in type 304 steel in hydrogen environment with high pressures, which provided the basis for the design and development of a high strength, hydrogen embrittle-resistant austenitic stainless steel.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 August 1982

K. Fässler and H. Spähn

1 Introduction Some interesting new developments have taken place in recent years in the field of ferritic stainless steel (1–16). As a material for chemical apparatus…

Abstract

1 Introduction Some interesting new developments have taken place in recent years in the field of ferritic stainless steel (1–16). As a material for chemical apparatus, the common highly alloyed chromium steels as listed in national standards (e.g. in the German Standard DIN 17440) have only found limited applications. The reasons are sensitivity of several of these chromium alloyed stainless steels to intergranular corrosion (especially after welding), lower corrosion resistance compared to austenitic stainless steels, and difficulties in fabricating (especially welding). It has been shown (1–16) that the intrinsic drawbacks of customary ferritics can be overcome by metallurgical measures, primarily keeping the amount of carbon and nitrogen extremely low. The solubility in the ferrite for these two elements in rather low, both occupying interstitial sites. Stainless steels of the type dealt with in this paper are therefore sometimes termed Extra Low Interstitial (ELI)‐ferritic stainless steels. At sufficiently low concentrations of carbon and nitrogen (and some other elements), the sensitivity of ferritic stainless steels to intergranular corrosion is definitely lowered, and their ductility at ambient temperature is increased, i.e. the transition temperature is lowered. An advantage of these steels is their resistance to stress corrosion cracking. They have, so far, shown no sensitivity against chloride stress corrosion cracking under realistic operating conditions. For this reason, cooling water systems using river water with a high chloride content represent a suitable field of application for these steels. They can be welded up to a wall thickness of 3mm without sensitisation and undue loss of impact strength so that tubes for heat exchangers can be made of these steels. Their development has led to alloys ranging from 18 Cr‐2 Mo‐0 Ni to about 28 Cr‐2 Mo‐4 Ni. The present paper will only deal with the 18 Cr‐2 Mo steel because this material can be compared in price and properties with the standard 18 Cr‐9 Ni‐2 Mo austenitic stainless steel. In addition, the material in question has now become available in the form of pipe and sheet.

Details

Anti-Corrosion Methods and Materials, vol. 29 no. 8
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 1 April 2005

M. Stanford and P.M. Lister

Cutting fluids despite playing an important role in metal cutting have considerable environmental impact. Inert gaseous metal cutting environments were investigated with…

1006

Abstract

Purpose

Cutting fluids despite playing an important role in metal cutting have considerable environmental impact. Inert gaseous metal cutting environments were investigated with the aim of removing soluble oil cutting fluids from metal cutting operations.Design/methodology/approach – Industrially reproducible cutting tests were devised, where an austenitic stainless steel and En32 low carbon steel material was milled in a range of different cutting environments. Tool life was measured for tests carried out in a number of gaseous environments and results were then compared with test results from conventional flood cutting environments.Findings – Low oxygen gaseous environments were compared with conventional cutting environments and a considerable flank wear reduction has been recorded using CVD coated tooling. Additionally flood coolant environments have been seen to promote chemical wear after the initial breakdown of coatings leading to rapid flank wear during milling of both En32 and austenitic stainless steel.Research limitations/implications – Only a limited number of work/tool material combinations have been investigated. A more detailed and exhaustive investigation is required to ascertain the scope of the improvements for a range of tool work combinations. This will assist in understanding the underlying reasoning for the tool life enhancement reported.Practical implications – All experimentation carried out is industrially reproducible. This work, therefore, proposes an environmentally clean alternative to the use of emulsified oils in metal cutting operations in order to exploit cost savings and improved operator working environments.Originality/value – Distinct operational performance improvements have been demonstrated in the form of extended tool life for metal cutting operations performed in a non‐polluting cutting environment. These findings could herald widespread advantages within the metal cutting community.

Details

Industrial Lubrication and Tribology, vol. 57 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 25 September 2009

Mumin Sahin

The purpose of this paper is to investigate mechanical and metallurgical variations at interfaces of commercial austenitic‐stainless steel and copper materials welded by…

Abstract

Purpose

The purpose of this paper is to investigate mechanical and metallurgical variations at interfaces of commercial austenitic‐stainless steel and copper materials welded by friction welding.

Design/methodology/approach

In this paper, austenitic‐stainless commercial steel and copper materials are welded using the friction welding method. The optimum parameters are obtained for the joints. The joints are applied to the tensile and micro‐hardness tests. Then, micro‐ and macro‐photos of the joints are examined.

Findings

It is found that some of the welds show poor strength depending on some accumulation of alloying elements at the interface result of temperature rise and the existence of intermetallic layers.

Research limitations/implications

It would be interesting to search about the toughness values and fatigue behaviour of the joints. It could be a good idea for future work to concentrate on the friction welding of these materials.

Practical implications

Friction welding can be achieved at high‐production rates and therefore is economical in operation. In applications where friction welding has replaced other joining processes, the production rate has been increased substantially.

Originality/value

The main value of this paper is to contribute to the literature on friction welding of dissimilar materials.

Details

Industrial Lubrication and Tribology, vol. 61 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 April 2004

Mümin Sahin and H. Erol Akata

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out…

3965

Abstract

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. Tension tests were applied to welded parts to obtain the strength of the joints. Fatigue properties were additionally obtained experimentally under fluctuated tensile loads. Finally, notch impact tests were applied to the joints. Microstructures using microphotographs were examined in the heat affected zone of welded parts. Hardness variations in welding zone were also obtained. Experimental results were compared with those of previous studies.

Details

Industrial Lubrication and Tribology, vol. 56 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 556