How q345r standard properties differ A36 steel properties

The company adheres to the "variety, quality and efficiency" road. We have established a technology center, a brand cultivation management system and a quality control system. Now the company has formed an independent innovation system integrating q345r standard production, learning, research and marketing. Our company has passed ISO9001 quality management system certification and ISO10012 measurement management system certification.

The toughness index of Q345B steel should be tested by impact test at 20 ℃. Although the strength of Q345B steel and Q345A steel are the same, the S / P control of Q345B steel is more strict, and the ambient temperatures of q345r standard, Q345B steel and Q345A steel are different. The cold impact test refers to the impact test at a certain temperature to obtain the energy consumed by punching the specimen. The more energy consumed, the higher the toughness of the material. Q345A is not subject to impact test. So Q345B steel is better than Q345A steel.

Compared with 15Cr steel, 20Cr alloy has higher strength and hardenability. The critical hardening diameter in oil is 4-22mm, and the critical hardening diameter in water is 11-40mm, but the toughness is poor. This q345r standard alloy steel q345r standard still has a tendency to grow grains during carburization, and direct quenching at lower temperature has a greater impact on impact toughness, so secondary quenching is required after carburization to improve the toughness of the core of the part, and there is no temper brittleness.

The strengthening mechanisms in metals mainly include solid solution strengthening, dislocation strengthening, fine grain strengthening, and second phase (precipitation and dispersion) strengthening. Alloying elements have the most significant strengthening effect on steel in the quenched and tempered state, because it makes full use of all four strengthening mechanisms. Martensite is formed during quenching, and carbides are precipitated during tempering, resulting in a strong second phase strengthening and greatly improving toughness. Therefore, obtaining martensite and tempering it is the most economical and effective comprehensive strengthening method for q345r standard.

q345r standard, No. 20 steel belongs to high-quality carbon steel.No. 20 steel means steel with an average carbon content of 0.20%;The thermal conductivity of No. 20 steel at 315℃ is 48 W/m℃;No. 20 steel is generally not quenched, the general treatment method is carburizing or normalizing;The yield strength of No. 20 steel is not less than 250MPa;The tensile strength of No. 20 steel is not less than 420MPa;Elongation of No. 20 steel is not less than 25%;The reduction of area is not less than 55%;The density of q345r standard and No. 20 steel is 7.85kg/cm3

We are the professional Chinese steel plate, steel pipe supplier. If you need any steel plate, steel pipe, we can put the steel plate, steel pipe order to our steel mill directly or collect these goods from our stock directly if we have enough ex-stock. Besides. if you need any q345r standard offer or if you want to know the price and any other information about steel plate, steel pipe price, please be free to contact us.

After-sales service team is a key department to test the steel quality. Product quality is always the foundation of our survival and development. The company's full inspection from raw materials to finished products; and implements standardized, scientific, and strict internal quality control and management systems in accordance with the process flow during the production process; products can only leave the factory if qualified, and follow-up problem solving systems are implemented in after-sales services to guarantee the customers’ interest.