A processing method of NPR steel rebar rod, wherein the NPR steel rebar is cold processed and has a yield strength of 800˜950 MPa, a tensile strength of 900˜1100 MPa, and a percentage elongation at maximum force of not less than 10˜40%;
- the processing method comprises the following steps:
- a placing step L20:
- fixing one end of a coil rack, and performing head-to-tail welding of the steel rebar at a front end of the steel rebar without stopping;
- an uncoiling step L30:
- providing a drawing force to a de coiler along a travel direction of steel rebar to preliminarily flatten the steel rebar, and synchronizing the de-coiler with a wire drawing machine through intelligent control equipment;
- a flattening step L40:
- repeatedly bending the steel rebar to remove a stress in the steel rebar using a wheel-rolling flattening method, so as to flatten the steel rebar without a scratch on its surface;
- a butt welding step L50:
- matching a diameter of the steel rebar by controlling current using PLC numerical control technology, welding the steel rebar according to a time required for steel rebar welding and current for welding, and automatically removing burrs on a welding surface of the steel rebar after welding is completed;
- a grit blasting step L60:
- automatically adjusting output of steel grit according to a diameter and surface requirements of the steel rebar to be processed, and processing oxide scales, and surface defects on the surface of hot-rolled NPR steel rebar inline, by using intelligent numerical control technology and communicating with a central master controller;
- a straightening step L70:
- after grit blasting, straightening the steel rebar by a straightening machine to make the steel rebar more straight;
- a pointing step L80:
- correcting or removing surface shape defects including waterline or ellipse of a head part of the steel rebar by using a pointing process, during each start of head threading process;
- a hydraulic head-pushing step L90:
- pushing the head part of the steel rebar to pass through a spiral mold, and setting a length of the head part of the steel rebar passing through the spiral mold;
- a cold drawn spiral ribbing step L10:
- forming spiral ribs on the steel rebar;
- a straight forward continuous wire drawing and traction step L11:
- pulling forward the raw material continually in a straight line, and repeatedly and alternately gripping and stretching the steel rebar forward by a rebar gripping device;
- a pre-straightening step L12:
- eliminating an internal stress of the steel rebar using a method of multi-wheeled crossed 360-degree curve rolling and straightening, without damaging the spiral ribs of the steel rebar during the pre-straightening process;
- a fine straightening step L13:
- performing fine straightening on the basis of pre-straightening, using a method of multi-wheel crossed or horizontal straightening;
- and
- a cutting-off step L14:
- cutting off the NPR steel rebar rod inline with an adjustable cutting length within 4˜12 meters per rod.