NM400 material meaning chemical composition and other common knowledge

ASTM A 53 NM400 material meaning covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A 53 NM400 material meaning is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.

The wear-resistant plate NM400 material meaning shows good wear resistance: the chemical composition of the alloy layer contains 4-5% carbon and 25-30% chromium. The volume fraction of Cr7C3 carbide in the metallographic structure is more than 50%, the macro hardness is HRC56-62, and the hardness of chromium carbide is HV1400-1800. Because of the vertical distribution of carbides in the wear direction, the wear resistance of the cast alloy with the same composition and NM400 material meaning hardness is more than twice as that of the cast alloy with the same composition and hardness. Compared with several typical materials, the wear resistance is as follows: (1) compared with low carbon steel; 20-25:1 (2) with as cast high chromium cast iron; 1.5-2.5:1.

The preparation of NM400 material meaning galvanized steel before welding is the same as that of ordinary low-carbon steel. It is necessary to carefully handle the groove size and nearby galvanized layer. In order to achieve penetration, the groove size shall be appropriate, generally 60 ~ 65 °, with a certain gap, generally 1.5 ~ 2.5mm; in order to reduce the penetration of zinc into the weld, the galvanized layer in the groove can be removed before welding. In the practical work, the centralized beveling, no blunt edge technology for NM400 material meaning centralized control, two-layer welding process, reducing the possibility of incomplete penetration.

The company adheres to the business philosophy of "good quality, customer first, honesty and trustworthiness", and strives to provide customers with high-quality NM400 material meaning products and excellent services. Our company's products NM400 material meaning are widely used in petroleum, chemical, power station, boiler and other industries, mainly used in reactors, heat exchangers, separators, spherical tanks, oil and gas tanks, liquefied gas tanks, nuclear energy reactor pressure shells and other equipment.

The company strengthens process management and pays attention to assessment. One of the key points of good service is to strengthen the process management and improve the evaluation mechanism. Make the after-sales service system more perfect and provide better service for customers.