.2 Cr13, Stainless Steel High-binding Structural Welding Process

As a kind of stainless steel,compared with other stainless steel, Martensitic stainless steel has lower price. But compared with carbon steel,it has such advertisement as anticorrosion,higher strength and less cost of lifespan. Now days,It is used for steam turbine fin,combustion engine air evacuation valve,medical equipment and petrochemical equipment,compared with other Martensitic stainless steel,2Cr13 is more used in the above field. in these fields, welding joint has low constraint degree,weld zone and heat-affected zone are affected so less from external condition during the time of coiling and shrinking after weld that it has less chance of arising weld defects. So it has more range of weld processing parameter and easy being welded and the research of general welding joint is complete, but for high constraint degree, because it has much higher requirement,now it has not a definite practical parameter and materials.According to the actual state and market demand of 2Cr13 stainless steel ,this article take high constraint degree as research point and select A317,A407,G217 as filled material ,use manual welding, Through the different welding process on track and nondestructive testing of typical welding joint microstructure analysis and mechanical performance testing, safely draw the research results。This article through to the three kinds of welding materials for multigroup trials that each filler material welding, 2Cr13 stainless steel structure of high constraint degree optimal processing parameters and different welding process parameters, and with the experiment phenomenon ultrasonic flaw detection nondestructive testing method to test the welding defects.In order to better explain test phenomenon, the paper also through a microscope equipment observed three kinds of welding materials of melting the deposited metal microstructure, according to weld microstructure, from frozen mode, grain size, etc explains three filler material welding defects reasons, through the analysis, the conclusion of solidification A407 electrode for AF mode, easy mode in austenitic grain boundaries leads to low melting point material, this model is more sensitive to temperature, when welding current exceeds the above 100A welding cracks easily produce; A317 electrode for FA mode, solidification mode because iron ferrite, dissolved Low melting and reduce the material form elements the formation of crack probability, when current control in 90-100A, interlayer temperature for 150 to 200℃, RuChongZhuang weld microstructure appears small ferrite + austenitic organization, prevent the cracks from extensions, its crack ability stronger; High-temperature tempering G217 electrode formed when a tempering saxhlet body that anti-cracking carbide organization, is stronger.Through the three material welding joint hardness testing, the hardness relative that reduced mother materials, and with the heat input increase, the cooling speed decrease.