Laser heat treatment hardening method for steel pipe cast iron roll surface

Abstract

The invention relates to a laser heat treatment hardening method for a steel pipe cast iron roll surface. The method comprises the steps of dividing an arc roll surface into 3-9 areas, spraying light-absorbing coatings on cast iron roll to be processed, and heating the roll surface to a micro-melting state by high-energy laser beams. A laser strengthened layer obtained by the method is metallurgically combined with a matrix, and is advantageous in that crystal grains are refined obviously, the thickness of the hardening layer ranges from 0.3 mm to 1.0 mm, the hardness reaches HV 620-760, the laser strengthened layer has good wear-resistance performance, and the lifetime of the roll is improved for 1-5 times. Moreover, according to the method provided by the invention, no subsequent process is needed after the laser hardening treatment of the steel pipe cast iron roll, and production cost is reduced. The method is practical and reliable, is convenient for operation, is environment-friendly, and has a great popularization value and huge social benefits.

Description

technical field [0001] The invention belongs to the surface modification of steel pipe cast iron rolls, in particular to a new method for laser hardening heat treatment on the surface of steel pipe cast iron rolls. Background technique [0002] Steel tube mill rolls are different from other types of rolling mill rolls in that: (1) The surface defects and rough surfaces of the tube blank produced by the upper stand are difficult to eliminate on the subsequent stand, which means that the steel tube rolls used in all stands should be It has good wear resistance; (2) The surface and bottom of the roll pass should have uniform hardness and wear resistance, which is especially important for large-diameter pipes. Therefore, the hardness of the bottom of the pass is usually used as an important indicator to measure the quality of steel pipe rolls. [0003] Domestic rolls for rolling seamless steel pipes are mainly made by machining rod-shaped billets, that is, first cast into rod-s...

AI Technical Summary

Problems solved by technology

However, the hardened layer obtained by laser phase transformation hardening treatment is relatively shallow, and cracks are prone to appear on the surface, which affects the service life of the roll

The content of the patent (01114853.5) involves the use of laser melting treatment technology to improve the surface properties of cast steel rolls, which significantly increases the steel passing capacity of cast steel rolls, but does not solve the problem of laser surface strengthening of seamless steel tube rolls

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