Improving The Surface Quality Of 300 Series Stainless Steel Products Based On The DOE Design

The wire rod production line in Dongbei Special Steel Company, which started trial in September 2009 and officially launched in January 2010, is a "four in one" short flow production line with the collection of steelmaking, refining, continuous casting and rolling. The design capacities of this production line are 320000 tons of steel billets and 300000 tons of steel products. The main equipments of the continuous rolling system include stepping girder furnace made by Germany LOI company, continuous rolling mill group made by Italy Danieli Company, the finishing mill group and reducing & sizing block made by Morgan Company; The productions contain austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, valves steel, spring steel, bearing steel, alloy structural steel, alloy tool steel, high-speed tool steel, cold heading steel, free cutting steel, and so on. The diameters of wire rods vary from 4.5 mm to 25 mm. However, the rolled products have not satisfied the design requirements, especially the main products 300 series stainless steel, since this line officially launched. The surface defects such as scars, scorings, scratches, laps, have a severe effect on the market sale of 300 series stainless steel.This paper focused on the surface defects on the 300 series stainless steel produced by Dongbei Special Steel Company. With the optimizing of DOE (Design of Experiment), heating process and rolling process in wire rod production line were optimization research, for heating and rolling processes with different factor collection, using the causal matrix and FMEA factor screening and optimization,In addition, the key factors (process parameters) such as furnace pressure, gas pressure, heating temperature, spinning temperature, finishing speed, clamping torque, which influenced the surface quality of 300 series stainless steel, were modified via DOE. The optimal process parameters were acquired finally, which increased the primary qualification ratio of 300 series stainless wire rod surfaces (Specification is less than 15 mm up to more than 93%, greater than 15 mm up to more than 50%).