Today most industrial plants especially in the oil and gas, offshore, sea water desalination, power generation industries work in very critical operating conditions and require more and more the use of special alloys resistant to corrosion and high temperatures.
钢钢碳content between 0.04% -2.3% of the iron-carbon alloys. In order to ensure its toughness and ductility, the carbon content of not more than 1.7%. The main elements of the steel in addition to iron, carbon, there are silicon, manganese, sulfur, and phosphorus.
Our highly-skilled manpower is dedicated to producing the finest quality steel pipe, pipe fittings, meeting a wide variety of material specifications. Their knowledge and experience of metal properties, welding procedures and quality control have set the pace and standard expected by our customers world-wide.
The primary raw material in pipe production is steel. Steel is made up of primarily iron. Other metals that may be present in the alloy include aluminum, manganese, titanium, tungsten, vanadium, and zirconium. Some finishing materials are sometimes used during production. For example, paint may be used if the pipe is coated. Typically, a light amount of oil is applied to steel pipes at the end of the production line. This helps protect the pipe. While it is not actually a part of the finished product, sulfuric acid is used in one manufacturing step to clean the pipe.
Steel can be categorized into four basic groups based on the chemical compositions:
Carbon steel is formed when two elements, iron and carbon, is combined with carbon being used as the alloying element.
Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties.
What Is Abrasion Resistant Steel
Some abrasion is intentional, such as sanding, grinding, and blasting. However, unintentional abrasion can lead to component failure so it is important to use the proper materials to ensure that surface wear does not lead to unanticipated breakdown of structures or parts. While steel in general has excellent resistance to abrasion, not all steels are equal.
How Does It Work?
The chemical composition of abrasion resistant steel is one of the attributes that make it more immune to wear than other types of steel. There are several alloys that can be used increase the abrasion resistance. Carbon helps block dislocations, which increases the hardness and strength of a steel. The added carbon also allows the steel to form microstructures with increased hardness when heated and quenched. There are other elements that can be added to abrasion resistant steel to increase its hardness value too. Chromium and manganese are also added to abrasion resistant steels to help reduce the negative effects caused by wear.
Heat treatment is another factor that helps the steel resist abrasion. Abrasion resistant steel must have a microstructure that allows it to have a high hardness. This is accomplished, in part, by adding the proper alloying elements. However, this alone is not enough to ensure the proper microstructure is formed. The steel must also undergo a heating and a rapid quenching process to form microstructures such as martensite and bainite which gives the steel the required high hardness values. Care must be taken when welding or heating abrasion resistant steels. If they are heated to a high enough temperature, it may have an annealing effect on the steel, causing it to lose some of its hardness and, therefore, its abrasion resistance.
What Types of Abrasion resistant pipes Are Available?
There are several different abrasion resistant steel grades. Each grade is typically made to a specific Brinell hardness value, as opposed to other steels that are made with tensile strength and toughness in mind. This is because hardness is one of the most important factors when trying to increase abrasion resistance.
Self-propagating high temperature synthesis (SHS)is used to describe a process in which the initial reagents (usually powders), when ignited, spontaneously transform into products due to the exothermitic heat of reaction.
A well-known example of SHS reaction is the thermite reaction given below:
Fe2O3 + Al → 2Fe + Al2O3
This reaction generates temperatures above the melting point of alumina and is used in the thermit welding process for joining railway lines.
Several other terminologies - such as combustion synthesis, gasless combustion or self-propagating exothermic reaction - are used to describe the process.
The types of material that can be formed using this process include metal borides, silicides, carbides, nitrides, sulphides, aluminides and oxides.
Steel is an alloy of iron and other elements. Some elements are intentionally added to iron for the purpose of attaining certain specific properties and characteristics. Other elements are present incidentally and cannot be easily removed. Such elements are referred to as “trace” or “residual” elements.
PMI (Positive Material Identification) testing is the analysis of materials to determine the chemical composition of a metal or alloy at particular (usually multiple) steps of alloy manufacturing or in-process alloy installation.
Many product specifications have mandatory requirements for reporting certain elements and these vary. Most mills routinely provide heat analysis which includes the elements below. Although it is possible to analyze for other elements this is most often not practical or necessary unless they are additions (e.g. Pb – Lead, Sb – Antimony, or Co - Cobalt).
Carbon是校长在钢硬化元素。Hardness and strength increase proportionally as the Carbon content increases up to about 0.85%. Carbon has a negative effect on ductility, weldability, and toughness. The carbon range in ULC Steel is usually 0.002 – 0.007%. The minimum level of Carbon in Plain Carbon Steel and HSLA is 0.02%. Plain
