scholarly journals Use of the Aging Effect to Change the Local Properties of Structure Components

2010 ◽  
Vol 137 ◽  
pp. 35-79 ◽  
Author(s):  
Mehdi Asadi ◽  
Nicole Schulze ◽  
Heinz Palkowski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Treatment ◽  
Heat Treating ◽  
Local Heat ◽  
Local Deformation ◽  
Strengthening Effect ◽  
Subsequent Aging ◽  
Local Heat Treatment ◽  
Local Properties

This research deals with processes leading to local strengthening effects in Advanced High Strength Steels (AHSS). Dual phase (DP), retained austenite (RA) - both hot and cold rolled - and complex phase (CP) steels have been investigated to examine the effect of thermal and mechanical processing parameters on local properties. For this purpose, a method has been investigated to achieve local strengthening, namely local deformation and local heat treatment. Samples were locally deformed by bending and embossing processes. A local deformation with defined pre-strains leads to enhanced hardness and strengthening. A subsequent aging treatment leads to a further increase in mechanical properties. Local heat treatment was applied using a laser and an electron beam. Following local heat treatment with selected parameters, the microstructure of the surface and the cross section as well as the mechanical properties were evaluated by light optical, scanning as well as transmission electron microscopy, hardness measurement, tensile testing and thermal modelling. It can be stated that with partial heat treatment, local high strengthening can be produced. At lower heat treating temperatures, this effect could be attributed to bake hardening. With increased heat treating temperature, the initial microstructure near the surface is affected. A model can be improved, which defines the correlation between the influencing parameters and the local properties. The influence of over-aging in locally strengthen regions has been studied. For this investigation, parameters are stable to locally adjust the strengthening effect. Partial strengthening of AHSS by local deformation or local heat treatment can open up new fields of applications for locally using the strengthening effect to only influence relevant areas of interest, thus providing the potential for saving energy and designing the component’s behaviour.

scholarly journals Microstructure Evolution and Mechanical Properties of AZ80 Mg Alloy during Annular Channel Angular Extrusion Process and Heat Treatment

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4223 ◽  
Author(s):  
Xi Zhao ◽  
Shuchang Li ◽  
Fafa Yan ◽  
Zhimin Zhang ◽  
Yaojin Wu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Annular Channel ◽  
Mg Alloy ◽  
Strengthening Effect ◽  
Β Phase ◽  
Angular Extrusion

Microstructure evolution and mechanical properties of AZ80 Mg alloy during annular channel angular extrusion (350 °C) and heat treatment with varying parameters were investigated, respectively. The results showed that dynamic recrystallization of Mg grains was developed and the dendritic eutectic β-Mg17Al12 phases formed during the solidification were broken into small β-phase particles after hot extrusion. Moreover, a weak texture with two dominant peaks formed owing to the significant grain refinement and the enhanced activation of pyramidal <c + a> slip at relative high temperature. The tension tests showed that both the yield strength and ultimate tensile strength of the extruded alloy were dramatically improved owing to the joint strengthening effect of fine grain and β-phase particles as compared with the homogenized sample. The solution treatment achieved the good plasticity of the alloy resulting from the dissolution of β-phases and the development of more equiaxed grains, while the direct-aging process led to poor alloy elongation as a result of residual eutectic β-phases. After solution and aging treatment, simultaneous bonding strength and plasticity of the alloy were achieved, as a consequence of dissolution of coarse eutectic β-phases and heterogeneous precipitation of a large quantity of newly formed β-phases with both the morphologies of continuous and discontinuous precipitates.

Designing Local Properties of Constructional Elements by Local Use of Ageing Effects in Multiphase Steels

2010 ◽  
Vol 638-642 ◽  
pp. 3062-3067 ◽  
Author(s):  
Mehdi Asadi ◽  
Heinz Palkowski
Keyword(s):  
Heat Treatment ◽  
High Strength ◽  
Local Heat ◽  
Processing Parameters ◽  
Strengthening Effect ◽  
Complex Phase ◽  
Heat Treated ◽  
Local Properties ◽  
Local Use ◽  
Multiphase Steels

The investigations deal with processes leading to local effects of strengthening in multiphase steels, being characterized by good formability, continuous yielding, high strength and a strong bake hardening and ageing effect. Dual phase and complex phase steels are under investigation to examine the effect of thermo-mechanical processing parameters on local ageing ability and its use for designed properties. For this purpose local heat treatment by laser are studied, as well as stability of local ageing on the adjusted strength. A remarkable increase of the hardness in the heat treated zone was observed. Stability of the local strengthening effect could be confirmed. Partial heat treatment of multiphase steels by laser can open a new field of application for the local use of the strengthening effect to influence only relevant areas, thus giving potential for energy saving.

LOCAL USE OF BAKE HARDENING IN MULTIPHASE STEELS FOR IMPROVED PROPERTIES IN STRUCTURES AND JOINTS

2008 ◽  
Vol 07 (02) ◽  
pp. 283-285
Author(s):  
HEINZ PALKOWSKI ◽  
ANNA BRUECK
Keyword(s):  
Heat Treatment ◽  
Automobile Industry ◽  
Steel Structure ◽  
Local Heat ◽  
Processing Parameters ◽  
Local Deformation ◽  
Strength Increase ◽  
Bake Hardening ◽  
Local Heat Treatment ◽  
Multiphase Steels

This paper investigates processes leading to local bake hardening (BH) effects in multiphase steels. The influence of the deformation path and of the temperature and duration of thermal treatments on strengthening in multiphase steels, in regard to both local and bulk properties of steel structure are investigated. Bake hardening is the ability of a metal, to harden during an annealing after forming, for example during the paint baking process in the automobile industry, delivering a post-forming strength increase of the final component. Multiphase steels such as dual phase (DP) and complex phase (CP) steels are investigated to examine the effect of thermo mechanical processing parameters on the local bake hardening ability of hot rolled DP and CP steels. For this purpose two methods of achieving local BH (local deformation and local heat treatment) are studied. The influence of a local deformation through bending on the work hardening, and bake hardening effects is examined. By locally limited laser treatment on cold-rolled material local BH can be reached through local heat treatment. Furthermore, the ageing stability of the gain in strength is examined.

Research of influence of heat treatment on metallophysical properties of metal of welded seams

2021 ◽  
pp. 412-419
Author(s):  
Николай Георгиевич Гончаров ◽  
Алексей Александрович Юшин ◽  
Олег Игоревич Колесников ◽  
Григорий Валерьевич Нестеров ◽  
Александр Игоревич Азарин
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wall Thickness ◽  
Welded Joints ◽  
Welded Joint ◽  
Local Heat ◽  
Strength Grade ◽  
Local Heat Treatment ◽  
Residual Hydrogen ◽  
Metal Properties

Цель настоящего исследования - оценка влияния локальной термической обработки (нормализации и закалки с отпуском для продольных сварных соединений труб, сваренных контактной сваркой токами высокой частоты, а также высокотемпературного отпуска и термического отдыха для кольцевых стыков трубопроводов, сваренных дуговой сваркой) на показатели механических свойств и металлургического качества металла сварных соединений. Для проведения исследований в области продольных сварных соединений использовались трубы диаметром 530 мм с толщиной стенки 10 мм класса прочности К56, для оценки свойств металла кольцевых стыков были выбраны катушки длиной 500 мм с односторонней симметричной разделкой кромок с углом скоса 30°, изготовленные из труб диаметром 219-530 мм с толщиной стенки 8-15 мм из сталей класса прочности К42, К48, К56. В частности, показано, что высокий отпуск повышает пластичность, снижает уровень остаточных сварных напряжений (более чем на 30 %), твердость и прочность. Термический отдых сварных стыков способствует снижению уровня остаточного водорода в металле сварных соединений, что позволяет повысить свариваемость трубной стали при проведении ремонтных работ. В целом сделан вывод о том, что локальная термообработка позволяет оптимизировать показатели механических свойств металла сварных соединений и при необходимости получать требуемый уровень механических свойств. The purpose of this study is to assess the effect of local heat treatment (normalizing and quenching with tempering for longitudinal welded joints of pipes welded through contact welding with high frequency currents, and high-temperature tempering and cooling for arc welded circular joints of pipelines) on the mechanical properties and metallurgical quality of welded joint metal. To carry out research in the field of longitudinal welded joints, pipes with a diameter of 530 mm and a wall thickness of 10 mm with the K56 strength grade were used; to assess the metal properties of ring joints, 500 mm long spools with unilateral symmetrical beveling with a bevel angle of 30°, made of pipes with a diameter of 219-530 mm with wall thickness of 8-15 mm made from K42, K48, K56 strength grade steel, were used. In particular, it is shown that high tempering increases ductility, reduces the level of residual weld stresses (by more than 30 %), hardness and strength. Cooling of welded joints helps to reduce the level of residual hydrogen in the welded joint metal, which increases the weldability of pipe steel during repair works. In general, it is concluded that local heat treatment allows to optimize the indicators of mechanical properties of the welded joint metal and, if necessary, to obtain the required level of mechanical properties.

CONDULOY

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Beryllium Copper ◽  
Hardening Heat Treatment

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.

ALUMINUM 319.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Rear Axle ◽  
Heat Treating ◽  
General Purpose ◽  
Temperature Performance

Abstract ALUMINUM 319.0 is a general-purpose foundry alloy that is moderately responsive to heat treatment. It has excellent casting characteristics and good mechanical properties. Among its many uses are crankcases, housings, engine parts, typewriter frames and rear-axle housings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as creep and fatigue. It also includes information on low and high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-256. Producer or source: Various aluminum companies.

ALUMINUM 62S

Alloy Digest ◽  
1953 ◽  
Vol 2 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Salt Water ◽  
Heat Treating ◽  
Magnesium Silicide ◽  
Age Hardening ◽  
Aluminum Company ◽  
Wrought Aluminum ◽  
Hardening Heat Treatment

Abstract ALUMINUM 62S is a magnesium silicide type of wrought aluminum alloy with high resistance to fresh and salt water corrosion. It responds to age hardening heat treatment for high mechanical properties. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-11. Producer or source: Aluminum Company of America.

UNS A97075

Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Applications ◽  
Structural Parts ◽  
Very High

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.

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