Production method of L80-9Cr martensitic stainless steel pipe

Abstract

The invention relates to a production method of an L80-9Cr martensitic stainless steel pipe. The production method comprises the following steps of (1) preparing a blank, specifically, centrifugally casting to produce a hollow pipe blank; (2) blank annealing, specifically, annealing the hollow pipe blank to reduce the hardness of the hollow pipe blank; (3) blank machining, specifically, machiningthe annealed hollow pipe blank, and removing air holes, shrinkage porosity and slag inclusion defects on the inner wall and the outer wall; (4) hot counterboring, specifically, heating to 1120-1160 DEG C, and performing the hot counterboring in a counterboring barrel; (5) hot extrusion, specifically, heating to 1160-1210 DEG C, and carrying out the hot extrusion deformation in an extrusion barrel;and (6) heat treatment, specifically, heating the steel pipe to 970-1000 DEG C, conducting air blowing and rapid cooling, heating again to 680-720 DEG C, and tempering to obtain the finished steel pipe; and the production system involves a centrifugal casting machine, an annealing furnace, blank machining equipment, a counterboring machine, a heat extruding machine and a heat treatment furnace. According to the production method of the L80-9Cr martensitic stainless steel pipe, a process route of centrifugal casting and hot extrusion is adopted, so that a production process is optimized, the loss of a riser is reduced, the metal yield is high, and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of seamless steel pipe production, and in particular relates to a method for producing L80-9Cr martensitic stainless steel pipes. Background technique [0002] L80~9Cr alloy elements are relatively high, the deformation resistance is large, and the hot working temperature range is narrow. It is a difficult-to-deform alloy. The hot piercing and rolling process is easy to produce sticking steel and crack defects. The hot extrusion process is that the steel pipe is formed under the action of three-way compressive stress, and the stress conditions are good, which has special advantages for the production of hard-to-deform high alloys. At present, the mature production methods are: smelting ingots - forging - annealing - forging billet peeling and car light - extruding billet inner drilling processing - hot extrusion molding - quenching and tempering treatment. For ingot forging, the riser should be cut off, and...

AI Technical Summary

Problems solved by technology

This patent application solves the difficult problem of high-carbon martensitic cold rolling and is not conducive to subsequent processing, but it cannot be used to produce L80~9Cr martensitic stainless steel pipes

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