Jiangyin Donghao Stainless Steel Tubing  
  Portugal | Japanese | Русский | España | Deutsch | English | Chinese Sitemap | Contact US



Tempering of Steel

Tempering is the process of reheating the steel leading to precipitation and spheroidisation of the carbides. The tempering temperature and time are generally controlled to effect the final properties required of the steel. The benefits resulting are the increase in the metal toughness and elongation. The negative effects are the reduction of the martensite (BCT) structure and the progression towards a spheroidal carbide + ferrite matrix structure.

Tempering steel is the process where an already hardened or normalized steel part is heated to a temperature below the lower critical temperature and cooled at a controlled rate to increase the ductility and toughness. Steel is tempered by reheating after hardening to obtain specific mechanical properties and also to relieve quenching stresses and to reduce dimensional instability. Tempering usually follows quenching from above the upper critical temperature; however, tempering is also used to relieve the stresses and reduce the hardness developed during welding and to relieve stresses induced by forming and machining.

The following affecting tempering : Tempering is affects the microstructure and the mechanical properties of a tempered steel which include:

  • Temperature
  • Time at temperature
  • Cooling rate from the tempering temperature
  • Steel Chemical Composition, i.e carbon content, alloy content, and other elements

In steel quenched to a microstructure consisting essentially of martensite, the iron lattice is strained by the carbon atoms, producing the high hardness of quenched steels. Upon heating, the carbon atoms diffuse and react in a series of distinct steps that eventually form Fe3C or an alloy carbide in a ferrite matrix of gradually decreasing stress level. The properties of the tempered steel are primarily determined by the size, shape, composition, and distribution of the carbides that form, with a relatively minor contribution from solid-solution hardening of the ferrite. These changes in microstructure usually decrease hardness, tensile strength, and yield strength but increase ductility and toughness.

Under some certain conditions, the hardness may unaffected by tempering or even be increased as a result of tempering. For example, tempering a hardened steel at very low tempering temperatures may cause no change in hardness but may achieve a desired increase in yield strength. Also, those alloy steels that contain one or more of the carbide-forming elements (chromium, molybdenum, vanadium, and tungsten) are capable of secondary hardening; that is, they may become somewhat harder as a result of tempering.

Share TubingChina.com All Rights Reserved

Directory | Standard | Heat | Heat Exchanger | Temperature | Pressure | Corrosion | Hardness | Surface | Properties | Selection of Stainless Steel | Contact US

Useful Tools:

Metals weight Calculator
Stainless Steel Weight Calculator
Nickel Alloy Tubing Weight Calculator
Sheet Plate Weight Calculator
Hardness Values Conversion Calculator
Hardness Conversion Calculator
Length Weight Temperature Volume Pressure Conversion
Pipe Working Pressure Calculation
Pressure Conversion Converter Calculator
Gauge Sizes - Wire Sheet Plate Tube
Stainless Steel Pipe Schdule
Nominal Pipe Size
ANSI Pipe Chart

Stainless Steel Tubing and Pipe:

Heat Exchanger Tubes
U Bend Stainless Steel Tubing
Duplex Stainless Steel Pipe
Boiler Tubes, Condenser Tubes
Stainless Steel Seamless Pipes Corrugated Seamless Stainless Steel Pipe Tube
Cold Drawn Bright Annealing Stainless Steel Tubes
Heat resistant Stainless Steel Tubes
Welded Stainless Steel Pipe
Corrosion Resistant Stainless Steel Tube
Corrosion Resistance of Stainless Steel Tubes
Nickel Alloy Seamless Tubes:

UNS N08020 2.4600 Nickel Alloy 20 Seamless Tubing
UNS N02200 2.4066 200 Nickel Alloy Seamless Tubing
UNS N04400 400 Nickel Alloy 2.4360 Nickel Alloy Tubing
UNS N08800 800 Nickel Alloy Seamless Tubes
UNS N08810 800H UNS N08810 Nickel Alloy Seamless Tubes
UNS N08811 800HT Nickel Alloy Seamless Tubes
UNS N08825 825 2.4858 Nickel Alloy Seamless Tubes
UNS N06600 600 2.4816 Nickel Alloy Seamless Tubes
UNS N06625 625 2.4856 Nickel Alloy Seamless Tubes
UNS N10276 C-276 2.4819 Nickel Alloy Seamless Tubing
Why Choose US?

Production Equipment
Testing Equipement
Qualification and Certificates
Quality Control Systerm
Service Range and Procedure

Contact US: