We Super Steel Manufacturing Co.,Ltd(SMC) are amongst the top manufacturers and suppliers for the seamless steel pipe, welded steel pipe, OCTG products and fittings from China. We have been manufacturing and supplying these products to the industry since 1993, and received repeat orders and appreciation from our valued customers.
High quality piping products from approved manufacturers.
In order to continuously improve our offerings to our clients, we have consistently improved and upgraded our manufacturing facility and can hence offer material with stringent requirements.
Over the years, Super Steel Manufacturing Co.,Ltd(SMC) has developed an enviable reputation for project management for the Oil & Gas, Construction, Power Energy, Marine & Offshore, Water Treatment, Exploration & Drilling Services, Pipeline & Petrochemical and other heavy industries.
The many years of experience that we have means that there is always someone who has the ability to carry a project forward.
Always up to date. In this column you can find the steel pipe related articles, including industry trends, product standards and materials, and some technical guidelines.
Heat treatment is essential for improving the strength, toughness, machinability, and overall performance of seamless steel pipes. Below is a clear overview of the major heat treatment methods widely used in industrial projects.
①Basic Heat Treatment Process for Seamless Steel Pipe
a. Heating:
Below Ac1: stabilizes the structure and relieves internal stress.
Above Ac3: fully austenitizes the steel.
b. Holding:
Ensures uniform internal temperature and results in a controlled microstructure.
c. Cooling:
Determines the final metallographic structure and mechanical properties. Common cooling methods include furnace cooling, air cooling, oil cooling, and water cooling.
②Normalizing Process for Seamless Steel Pipe
Normalizing heats the pipe above the austenitizing temperature, holds it, and cools it uniformly in air.
Main purposes:
Refine grains and homogenize the microstructure.
Eliminate banded structures and network carbides.
Improve machinability for carbon and low-alloy steels.
Serve as pretreatment before quenching to reduce defects.
Replace annealing for general-purpose seamless steel pipes with lower performance requirements.
③Annealing Process for Seamless Steel Pipe
Annealing heats the pipe above or below Ac3/Ac1, holds it, and slowly cools it to achieve a near-equilibrium microstructure.
Functions:
Lower hardness and strength.
Improve ductility and machinability.
Eliminate internal stress and structural inhomogeneity.
Provide a stable microstructural foundation for final heat treatment.
④Tempering Treatment for Seamless Steel Pipe
Tempering heats the pipe below Ac, holds it, and cools it appropriately to achieve a stable and tough microstructure.
Purposes:
Improve toughness and plasticity.
Reduce residual quenching stress.
Stabilize dimensions during service.
Temperature ranges:
Low tempering: 150–250°C
Medium tempering: 350–500°C
High tempering: 500–650°C
⑤Quenching Process for Seamless Steel Pipe
Quenching heats the pipe to 30–50°C above Ac3, holds it, and rapidly cools it to form martensite (M) and bainite (B).
Features:
High hardness and strength but increased brittleness.
Generates internal thermal and structural stress.
Typically followed by tempering (Q+T) to achieve balanced mechanical properties.
⑥Solution Treatment for Stainless Seamless Steel Pipe
A high-temperature quenching process used mainly for austenitic stainless seamless steel pipes.
Purpose:
Reduce hardness and strength.
Improve plasticity and toughness.
Enhance corrosion resistance.
Restore uniform austenitic structure and meet performance standards.
English
Español
Français
بالعربية
