Fogningsforskning på Swerea KIMAB · · 2015-06-07• Introduction of high strength steels in fatigue loaded welded structures • Light weighting through sandwich structures •

2015-06-07

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Fogningsforskning på Swerea KIMAB SvK Forskningsseminarium

2015-06-08

Karl Fahlström, Paul Janiak, Kjell-Arne Persson,

Joakim Wahlsten & Joakim Hedegård

Centre for Joining and Structures (FogningsCentrum + Hållfasthetsektionen)

2015-06-07

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CJS - ”Centre for Joining and Structures”

• Network for joining activities & joining research

• Member programme

• Project generation

• Cross-functional

• Knowledge building

• Applied research

Centre for

joining and

structures

optimized

construction joining

technologies

weldability

joint

properties

properties

in service

failure

analysis

repair

non

destructive

testing

Some members:

General knowledge projects within:

• New processes – New materials

• Optimization – Evaluation – Simulation – Testing

• Increased understanding – Mechanisms – Models

Main application areas with projects within…

…stainless steels:

ex power generation,

tubes & pipes

…heavy industry:

thicker materials

ex dumpers, bridges

…automotive industry:

thinner materials

ex BiW, hang-on parts

Cross-functional and directed research projects within

“Centre for Joining and Structures”

2015-06-07

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CJS in one slide

Base projects Only full members can participate

Application projects Closed – typically one

member, only possible

for full members

Open – All members

can participate

CJS Associate members

Seminars, network,

conferences

Bank with ideas for

larger projects

CJS Full members

Title:

Start: End: Budget: Funding from:

INNODEFAB - INNOvative concepts for lightweight DEsign and FABrication of welded high strength steel structures

Dec 2014 Dec 2016 8100 KSEK Vinnova

Target/main goal:

INNODEFAB focuses to develop and demonstrate new light weight concepts and

manufacturing technologies for infrastructure, heavy vehicles and material handling.

Through:

• Introduction of high strength steels in fatigue loaded welded structures

• Light weighting through sandwich structures

• New manufacturing methods with high productivity and fatigue life extending effects

Results from this project contribute to:

• Less material and energy usage

• Better understanding of fatigue life prolonging measures

• Reduce cost of manufacturing and maintenance

2015-06-07

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Title:

Start: End: Budget: Funding from: Oct 2014 June 2017 8000 KSEK Vinnova

The project will develop a non destructive test method, based on laser

ultrasonic (LUS) with the aim to enable automated quality assurance of

joints in an industrial environment.

Expected results and benefits:

• Prototype: Robust, automated non-destructive test method

• Early on-line detection of joint defects

• Minimize the number of defect products produced

• Speed-up implementation of new materials in production

Target/main goal:

QUALITY II - Advanced quality assurance of joints

Title:


Target/main goal:

Develop an accurate on-line measuring system (MS) and thereby:

Design and optimize algorithms for weld surface geometry

Identify quality affecting parameters and

enable improved process control resulting in reduction of

overproduction, rework and over processing.

Contribute to improved competitiveness and sustainable

manufacturing through increased product life, quality

and reduced environmental impact

Evaluate and demonstrate an automated geometrical

quality assurance system in production environments

Study required conditions for an ANN (artificial neural network)

intended for improved control of manufacturing processes

Identify possibilities to enable adaptive process control of

joining technologies

ONWELD “new ON-line method for quality assurance of WELDed strucutres”


Reference block + gauge

MS + built-in softwares

MS + Algorithm

2015-06-07

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Title:


ONWELD “new ON-line method for quality assurance of WELDed strucutres”


Title:


This project will proceed with the developed technique from the projects

Quality and ongoing ONWELD in new application areas, to analyse and

understand the connection between design, process parameters, weld quality

and how this affects the variation in fatigue life of welded structures.

April 2014 Dec 2015 1 400 KSEK SK (internal Swerea)

SK-QFAT - Quality assurance and FATigue assessment

2015-06-07

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Title:


SK-QFAT - Quality assurance and FATigue assessment April 2014 Dec 2015 1 400 KSEK

The project is carried out in close collaboration between Swerea KIMAB

(Joining technology & Swerea virtual lab), KTH and with interested

companies; SSAB, HIAB, VCE

The main goal is to better understand how different imperfections affect the

fatigue life of a component and to be able to predict the fatigue properties

SK (internal Swerea)

Title:


Target/main goal:

Project description:

Jan 2015 Dec 2015 300 KSEK CJS (Base)

This project will study if and when compressive residual stresses from post weld treatments are relaxed. The

relaxation could occur from overloads in the spectrum or possibly in high cycle fatigue.

Variable amplitude:

Study residual stress relaxation at different peak loads around 80% of the yield strength. Guidelines state

that HFMI treatments are valid up to 80% of the materials yield strength.

Long term effects:

Perform comparative high cycle (>5e6) fatigue studies of HFMI and non HFMI treated joints. Compare

with FAT values for the chosen sample geometry.

The main target of this project is to develop knowledge of the fatigue resistance of HFMI-treated

welded joints under variable load conditions and long service life.

Long term- and variable amplitude effects on HFMI treated Joints

2015-06-07

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Title:


BENFAT – Benefits of using High strength steel in Low-Cycle Fatigue applications

Apr 2015 Dec 2015 152 KSEK CJS

This project aims to investigate if there is any benefits from using HSS in low cycle

fatigue. Notch stress calculations show that, for certain joint configurations, in the

low cycle region (10.000 – 100.000) there may be a benefit of using high strength

steels, HSS.

A master thesis work will be launched within the scope of this project.

Focus will be on production of experimental results to verify simulations and in

order to best compare differences between welded materials.

Specimen type: transversal attachment

Material: S960 (ref. 355) thickness 4 mm

Filler mtrl: Cored wire, e.g. Coreweld 89

Two phase fatigue testing: Phase I : -as welded

Phase II: -machined weld toe

Title:


Target/main goal:


Jan 2015 Dec 2015 336 KSEK CJS (Base)

LTT have been reported to improve fatigue life in many situations due to the initiation of compressive

stresses in the weldment. This is true for crack initiation from the toe side. Recent studies (Work in

progress) have however indicated that when a crack is initiates from the root side the LTT material might

loose its fatigue life extension properties and instead regular filler materials are preferred.

This project intends to verify this by both simulation of the residual stress state when using LTT compared

to conventional fillers as well as with experimental fatigue tests.

Study the benefits of using LTT in load carrying cruciform joints with crack initiation from the root side

Fatigue root crack in Post weld treated joints

Ms200 (LTT) Ms420 (Conventional filler)

2015-06-07

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Title:


Target/main goal:


May 2015 Dec 2015 339 KSEK CJS (Appl)

In high performance MAG welding, such as Rapid Processing, Force Arc etc., it is not unusual that the

porosity is high. Even if the influence on mechanical properties is limited, high levels of porosity creates an

uncertainty of the quality of the weld.

The aim of this project is to reduce porosity in high performance (high deposition rate) MAG

welding of steel.

High productivity MAG-welding

Title:

Start: End: Budget: Funding from: March 2014 Dec 2014 290 KSEK CJS (Appl)

Target/main goal:


MAG welding of thicker material often results in distortions that need to be straightened or may

else lead to difficulties in the subsequent manufacturing processes.

New technologies such as the use of LTT welding wires can reduce the residual stress levels and

thereby the distortions. By combining different welding methods the weld size and the distortion

can be reduced.

The project aims at minimizing and quantifying the distortion by:

• Using LTT filler metals (martensitic solidification with volume increase at solidification)

• Use larger root face together with keyhole welding of the root pass with forceTIG.

• To gain knowledge on how different joint types welded with different processes and

the use of LTT wire compare to normal welding techniques.

Minimize weld deformation in 8-20mm material

2015-06-07

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Distortion control in laser welding of UHSS

Increased use of UHSS

Increased use of laser beam

welding

Manufacturing

Simulation

Fixturing & process

Lighter and stronger

Occurring distortions during welding…

…needs to be controlled and understood!

2015-06-07

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Framework

Vinnova FFI – Hållbar produktion

Total budget: 14,8 MSEK

Time frame: 2013-01-01 – 2015-12-31

WP1

Type cases for experiments

• Identification of typical BIW-applications of laser beam welding

• Definition of type cases for experimental verification

WP2

Simulation of laser beam welding

• Generation of material data for simulations

• Simulations in different software packages

• Verification of welding experiments in WP3

WP3

Innovative methods for distortion minimization

• Experimental welding and measurement of geometrical distortions

• Iterations of information exchange between simulation and experiments to find optimal process

WP4

Demonstration

• Implementation of innovative welding methods in BIW part or full structure

WP5

Guidelines

• Results from WP1-WP4 are presented through guidelines of laser beam welding methods for minimization of geometrical distortions in automotive industry

Work packages

2015-06-07

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Geometries and material grades

Type cases chosen simulating A- and B-pillar

Grades used (t = 1.0 mm):

• MBW-1500P

• Docol 1700M

• DP800

• Docol 200

Weld clamping and sequence

Clamping designed for research • 10 clamps in total

• 5 clamps on each flange

• Individually controlled by pneumatics

Weld sequence • Welding along flanges

• Cooling after welding

• Unclamping in sequence

2015-06-07

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Title:


Target/main goal:

• Robust processes for welding die casted Mg-, Al- and extruded Al alloys.

• Guidelines for welding of cast and extruded light weight metals available.

Castma Oct 2014 July 2017 Vinnova 7500 KSEK

Casted components in light weight material has during a long time been used within the automotive

industry. Complex structures can be produced easily, where forming from sheets would have been

expensive and time consuming. Magnesium (Mg) alloys and Aluminium (Al) alloys are favorable due to

their low weight and good mechanical properties.

Joining of die casted Mg and Al are conventionally done by mechanical joining processes like bolting

or self-piercing riveting, or even with adhesive bonding. The mechanical joining technique, compared

to welding, gives beneficial properties since the material not is heat affected. Welding should be

carefully controlled since it could be problematic due to that casted metals may contain inclusions and

defects from the casting process. Also common welding defects such as cracking and porosity must

be considered while welding these light weight metals.

Title:


Castma

Porosity (mainly related to hydrogen or shrinkage but also gas entrapment during welding due to, for

instance keyhole instability in laser welding Al)

Cracking (hot cracking, in aluminium Cu and Mg typically cause problems)

Oxide inclusions or oxide films

Loss of alloying elements

Undercut

Aging (over-aging in the HAZ)

These will all have an influence on the mechanical properties such as

Hardness

Tensile strength

Fatigue strength

Corrosion properties

Typical problems when welding cast Mg- and cast Al alloys

2015-06-07

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Title:


Target/main goal:


The aim of this project is to investigate the properties of very short flanges that are welded with

laser welding. Strength and geometry properties are the main issue.

Shorter flanges on vehicles are an effective way to minimize weight. Resistance spot welding need several

extra mm, excluding the actual weld, to ensure a stable process. If another joining technique could be used,,

the flanges could be designed in a more compact way resulting in less weigh of the component. Focus in this

project would be comparison between butt joint vs. lap joint including strength tests for flanges. Heat

conduction and crack sensitivity are of interest.

.

Properties of extremely short welded flanges Jan 2015 Dec 2015 100 KSEK CJS (appl.)

Title:


Target/main goal:

Investigate and, if possible, explain differences in resistance spot welding of boron steel coated

with AlSi 80 g/m2 compared to AlSi150 g/m2.

AS80 instead of AS150 Jan 2014 Dec 2014 119 KSEK CJS (Appl)

0

20

40

60

80

100

0 20 40 60Co

nc. (w

eig

ht%

)

Depth (µm)

GDOES Profile AlSi80

2015-06-07

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Title:


Target/main goal:


The aim of this project is to investigate the weldability of very high strength boron steels

• Martensitic HSS + carbon High strength + High hardness

• Carbon equivalent is higher than 0.5 (recommended 0.2 – 0.5)

• High cooling rate from laser welding martensite formation

Hard and brittle welds that may results in cracking! Weldability?

Weldability of 1800 & 1900 MPa boron steels 2013 2015 CJS (appl.)

What is multi material design?

• ”Multimaterialkonstruktion (MMK)” definieras som en avsiktlig kombination av

två eller flera material som kompletterar varandra på ett sådant sätt att nya

överlägsna funktioner & egenskaper skapas

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a)

b)

a)

b)

Background:

- Possibility to influence on the governmental strategic research areas within FFI.

- First idea was presented at VINNOVA in mid April. Now 1/6 proposals for

continuation. Decision will be given in the end of 2015. Program start 2016.

Multi material design

2015-06-07

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Lättviktspotential för multimaterial

Lättviktspotential för enskilda material

Höghållfast Stål

Ultra Höghållfast Stål

Borstål

Al / Mg legeringar

Lätt

vikt

spo

ten

tial

Tid

Innovativa lösningar i fokus

• Nödvändigt att tänka nytt!

• Viktigt att korskoppla olika kompetenser

• Inte bara innovativitet för lättvikt utan även multifunktionalitet

• Låg TRL idag, måste komma hela vägen till implementering

• Viktigt med helhet för att inte sub-optimera, inte byta ut enstaka delar

En större satsning krävs!

Stor vinning, banbrytande resultat

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Title:


Target/main goal:


The aim of this pre-study is to lay the ground for a new computerized, easy-to-use, guideline for

welding of duplex stainless steel that relates welding metallurgy and mechanical- and corrosion

properties of the joint to the welding operation parameters used. These recommendations will help

material suppliers, designers, welders and welding engineers in their work with welding of duplex

stainless steels, and will take into account; heat input, welding method, steel grade, welding

consumable grade, shielding and backing gas, material thickness and joint geometry.

The pre-study is combining experimental methods, thermodynamical modelling and computational weld

simulations to be used to provide the data needed to build a weld prediction software tool for welding of

duplex stainless steels.

DuplexWeld Prediktering av mikrostruktur och egenskaper i

svetsar av duplexa rostfria stål

Aug 2014 June 2015 1 670 KSEK Vinnova

2015-06-07

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Title:


Ström

Antal strängar

Materialtjocklek

Rotgas

Skyddsgas

Fogtyp

Grundmaterial

Tillsatsmaterial

Spänning

Svetsmetod

Mellansträngstemp.

Nitridutskiljning

Ferrit/Austenit-balans

Sigma-fas

Rekommendationer

för svetsning

Mekaniska- och korrosions-

egenskaper

DuplexWeld

-datorverktyg



Aug 2014 Aug 2015 1 670 KSEK

Title:


• A structure of an interface and a prototype version of the computerized tool recommendations

for welding of duplex steels

• Investigation of the possibilities of thermodynamic modeling and simulation tools for the

prediction of the microstructure of welded joints of single and multiple strings

• State-of- the-art in the field of thermal cycling and microstructure / trait prediction of duplex

stainless steels

• Summary of welding recommendations for duplex grades from the participating companies

and the available literature

• Identification of knowledge gaps and barriers to the development of a comprehensive tool

for welding recommendations for duplex grades



2015-06-07

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Title:


Target/main goal:

Guidelines for use of welded stainless steel in corrosive environments

JOINOX Sep 2012 Feb 2016 RFCS

Co-ordinator: Núria Fuertes Casals, Swerea KIMAB AB

Arc energy [kJ/mm] 4R: 1.22

4N: 1.17

4HE: 1.06

Figure 1. Temperature recorded at various positions for the welded joint for duplex grade 2507.

The welding process used was GTAW and arc energies are given in the figure.

weld pool

pale yellow

straw yellow

dark yellow

brown

purple brown

purple

blue

dark blue

weld pool

Figure 2. Example of heat tint spectrum within HAZ,

(a) welded joint, (b) example of colour chart with RGB values for different heat tint zones.

Colour Temperature, °C

Dark blue 960

Blue 870

Purple 770

Purple brown 680

Brown 580

Dark yellow 480

Straw yellow 380

Pale yellow 290

Arc energy [kJ/mm] 4R: 1.22

4N: 1.17

4HE: 1.06

Figure 1. Temperature recorded at various positions for the welded joint for duplex grade 2507.

The welding process used was GTAW and arc energies are given in the figure.

weld pool

pale yellow

straw yellow

dark yellow

brown

purple brown

purple

blue

dark blue

weld pool

Figure 2. Example of heat tint spectrum within HAZ,

(a) welded joint, (b) example of colour chart with RGB values for different heat tint zones.

Title:


JOINOX

2015-06-07

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Title:


Production of a broad range of heat tints

- Laboratory welded joints manufactured

- Industrial welds manufactured to be compared to laboratory practice

- 41 unique weld joints combinations with different heat tint.

- Influence of welding processes, alloying elements, shielding gas, heat input, welding technique, etc.

Efficiency of post-weld cleaning methods:

- Mechanical processes: Brushing, Brushing + polishing

- Chemical processes: Brushing + pickling paste, Brushing + acid bath

JOINOX

Title:


JOINOX

Detailed characterisation of oxides:

- Advanced techniques have been used for studying the level of discoloration, composition,

thickness and semi-conductivity type of heat tints.

Evaluation of corrosion resistance:

- Uniform corrosion and long-term exposures in acidic/basic and mild environment

- Advanced localised corrosion techniques

- End-user environments

0 0.1 0.2 0.3 0.4 0.5 0.6 0.70

10

20

30

40

50

60

70

80

Depth(µm)

Weig

ht

%

2205 GMAW HAZ at 6 mm

Fe

Cr

Ni

O

Mo*10

Mn*10

Si*10

Fig 45. Potentiodynamic test on duplex 2507 FCAW (left) and 2507 GMAW (right).

1 mA/cm2 1 mA/cm2

20 mV/min

1 M NaCl

89 °C

20 mV/min

10 mV/min

1 M NaCl

89 °C

some crevice (black line)

pits

2015-06-07

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Title:


Target/main goal:

Perform a literature study and identify helpful tools for joining

carbon steel to stainless steels, sensitive to heat treatment.

Produce a PowerPoint presentation identifying possible risks

and how to avoid them

In dissimilar metal welding there is a risk for

detrimental changes of joint:

• Corrosion properties

• Mechanical properties

• Weld defects – hot cracking, ductility cracking,

post weld cracking, stress corrosion cracking,

etc.

These changes can be caused by dilution of the

filler metal by parent material

as well as diffusion of chemical elements and

influence of the thermal cycle during and after

welding.

Joining of stainless steel to carbon steel Jan 2014 Dec 2014 333 KSEK CJS (Base)

This may lead to special demands on factors

such as:

• Joint design, joint preparation, cleaning

procedures, clamping

• Selection of filler metals and shielding gases

- transition materials and/or special filler

metals

• Control of heat input, cooling rate, pre-

heating, interpass temperature (first layer

and top layers)

• Post weld heat treatment, post weld work

• Testing

Title:


Target/main goal:

The objective with the project was to evaluate possibilities and risks by minimizing the heat input

(with the so called “cold welding methods”) in a butt weld between austenitic and duplex stainless

steel and in overlay welds with a cladded super-duplex layer on carbon steel.

• Risk for lack of fusion or debonding and proposals on how to avoid this risk

• Risk for precipitation of brittle phases and proposals on how to avoid this risk

CMT- II Jan 2014 Dec 2014 403 KSEK CJS (Appl)

CMT robot welding

2015-06-07

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Title:


Target/main goal:


Optimize the weld parameters and welding technique in CMT welding super-duplex stainless steel

to fully austenitic stainless steel in order to minimize the risk for lack of fusion and sharp weld toes.

This project is a continuation of the CJS project CMT II

This project will focus on welding highly alloyed material such as 2507 and 254 SMO.

Issues with cold methods - CMTIII Jan 2015 Dec 2015 333 KSEK CJS (Appl)

Title:


Target/main goal:


Study braze welding and brazing in ovens of high alloyed stainless steels such as duplex, super-

duplex and super-austenitic stainless steels . Of special concern is how Cu braze material affects

the joint.

The knowledge of the properties of brazed joints in duplex, super duplex and super austenites is limited.

Risk for defects (such as risk for liquation cracking), corrosion issues and mechanical properties as well as

joint design, cleaning and brazing procedure (best practice) will be part of the project.

The project will include a literature survey and experimental part with selected brazing processes.

Braze welding of highly alloyed stainless steels Jan 2015 Dec 2015 300 KSEK CJS (Base)

Documents

Fogningsforskning på Swerea KIMAB · · 2015-06-07• Introduction of high strength steels in fatigue loaded welded structures • Light weighting through sandwich structures •