Joining dissimilar stainless steels for pressure vessel components

Zheng Sun, Huai-Yue Han

Research output: Book/ReportReport

Abstract

A series of studies was carried out to examine the weldability and properties of dissimilar steel joints between martensitic and austenitic stainless steels - F6NM (0Cr13Ni4Mo) and AISI 347, respectively. Such joints are important parts in, e.g. the primary circuit of a pressurized water reactor (PWR). This kind of joint requires both good mechanical properties, corrosion resistance and a stable magnetic permeability besides good weldability. The weldability tests included weld thermal simulation of the martensitic steel for investigating the influence of weld thermal cycles and post-weld heat treatment (PWHT) on the mechanical properties of the heat-affected zone (HAZ); implant testing for examining the tendency for cold cracking of martensitic steel; rigid restraint testing for determining hot crack susceptibility of the multi-pass dissimilar steel joints. The joints were subjected to various mechanical tests including a tensile test, bending test and impact test at various temperatures, as well as slow strain-rate test for examining the stress corrosion cracking tendency in the simulated environment of a primary circuit of a PWR. Based on the weldability tests, a welding procedure -tungsten inert gas (TIG) welding for root passes with HNiCrMo-2B wire followed by manual metal arc (MMA) welding using coated electrode ENiCrFe-3B - was developed and a PWHT at 6000C/2h was recommended. Furthermore, the welding of tube/tube joints between these dissimilar steels is described. The joints made with the welding procedure that was developed are not susceptible to hot or cold cracking. The joints, after PWHT, exhibit both satisfactory mechanical properties and stress corrosion cracking resistance. A prototype product was made and subjected to pressure testing. The results of various tests indicated that the quality of the tube/tube joints is satisfactory for meeting all the design requirements.
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages30
ISBN (Print)951-38-4484-6
Publication statusPublished - 1994
MoE publication typeNot Eligible

Publication series

SeriesVTT Tiedotteita - Meddelanden - Research Notes
Number1550
ISSN1235-0605

Fingerprint

Pressure vessels
Joining
Weldability
Welds
Stainless steel
Martensitic steel
Welding
Pressurized water reactors
Heat treatment
Stress corrosion cracking
Mechanical properties
Steel
Testing
Inert gas welding
Martensitic stainless steel
Magnetic permeability
Networks (circuits)
Electric arc welding
Bending tests
Heat affected zone

Keywords

  • stainless steels
  • joining
  • welding
  • pressure vessels
  • martensitic stainless steels
  • austenitic stainless steels
  • nuclear reactors
  • pressurized water reactors

Cite this

Sun, Z., & Han, H-Y. (1994). Joining dissimilar stainless steels for pressure vessel components. Espoo: VTT Technical Research Centre of Finland. VTT Tiedotteita - Meddelanden - Research Notes, No. 1550
Sun, Zheng ; Han, Huai-Yue. / Joining dissimilar stainless steels for pressure vessel components. Espoo : VTT Technical Research Centre of Finland, 1994. 30 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1550).
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Sun, Z & Han, H-Y 1994, Joining dissimilar stainless steels for pressure vessel components. VTT Tiedotteita - Meddelanden - Research Notes, no. 1550, VTT Technical Research Centre of Finland, Espoo.

Joining dissimilar stainless steels for pressure vessel components. / Sun, Zheng; Han, Huai-Yue.

Espoo : VTT Technical Research Centre of Finland, 1994. 30 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1550).

Research output: Book/ReportReport

TY - BOOK

T1 - Joining dissimilar stainless steels for pressure vessel components

AU - Sun, Zheng

AU - Han, Huai-Yue

PY - 1994

Y1 - 1994

N2 - A series of studies was carried out to examine the weldability and properties of dissimilar steel joints between martensitic and austenitic stainless steels - F6NM (0Cr13Ni4Mo) and AISI 347, respectively. Such joints are important parts in, e.g. the primary circuit of a pressurized water reactor (PWR). This kind of joint requires both good mechanical properties, corrosion resistance and a stable magnetic permeability besides good weldability. The weldability tests included weld thermal simulation of the martensitic steel for investigating the influence of weld thermal cycles and post-weld heat treatment (PWHT) on the mechanical properties of the heat-affected zone (HAZ); implant testing for examining the tendency for cold cracking of martensitic steel; rigid restraint testing for determining hot crack susceptibility of the multi-pass dissimilar steel joints. The joints were subjected to various mechanical tests including a tensile test, bending test and impact test at various temperatures, as well as slow strain-rate test for examining the stress corrosion cracking tendency in the simulated environment of a primary circuit of a PWR. Based on the weldability tests, a welding procedure -tungsten inert gas (TIG) welding for root passes with HNiCrMo-2B wire followed by manual metal arc (MMA) welding using coated electrode ENiCrFe-3B - was developed and a PWHT at 6000C/2h was recommended. Furthermore, the welding of tube/tube joints between these dissimilar steels is described. The joints made with the welding procedure that was developed are not susceptible to hot or cold cracking. The joints, after PWHT, exhibit both satisfactory mechanical properties and stress corrosion cracking resistance. A prototype product was made and subjected to pressure testing. The results of various tests indicated that the quality of the tube/tube joints is satisfactory for meeting all the design requirements.

AB - A series of studies was carried out to examine the weldability and properties of dissimilar steel joints between martensitic and austenitic stainless steels - F6NM (0Cr13Ni4Mo) and AISI 347, respectively. Such joints are important parts in, e.g. the primary circuit of a pressurized water reactor (PWR). This kind of joint requires both good mechanical properties, corrosion resistance and a stable magnetic permeability besides good weldability. The weldability tests included weld thermal simulation of the martensitic steel for investigating the influence of weld thermal cycles and post-weld heat treatment (PWHT) on the mechanical properties of the heat-affected zone (HAZ); implant testing for examining the tendency for cold cracking of martensitic steel; rigid restraint testing for determining hot crack susceptibility of the multi-pass dissimilar steel joints. The joints were subjected to various mechanical tests including a tensile test, bending test and impact test at various temperatures, as well as slow strain-rate test for examining the stress corrosion cracking tendency in the simulated environment of a primary circuit of a PWR. Based on the weldability tests, a welding procedure -tungsten inert gas (TIG) welding for root passes with HNiCrMo-2B wire followed by manual metal arc (MMA) welding using coated electrode ENiCrFe-3B - was developed and a PWHT at 6000C/2h was recommended. Furthermore, the welding of tube/tube joints between these dissimilar steels is described. The joints made with the welding procedure that was developed are not susceptible to hot or cold cracking. The joints, after PWHT, exhibit both satisfactory mechanical properties and stress corrosion cracking resistance. A prototype product was made and subjected to pressure testing. The results of various tests indicated that the quality of the tube/tube joints is satisfactory for meeting all the design requirements.

KW - stainless steels

KW - joining

KW - welding

KW - pressure vessels

KW - martensitic stainless steels

KW - austenitic stainless steels

KW - nuclear reactors

KW - pressurized water reactors

M3 - Report

SN - 951-38-4484-6

T3 - VTT Tiedotteita - Meddelanden - Research Notes

BT - Joining dissimilar stainless steels for pressure vessel components

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Sun Z, Han H-Y. Joining dissimilar stainless steels for pressure vessel components. Espoo: VTT Technical Research Centre of Finland, 1994. 30 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1550).