Quality assurance measure

Quality assurance measureQuality assurance measure

1. steeturel structrue quality control measures

1.1 raw material and equipment quality control
Certificate shall be accompanied by quality steel, according to the furnace batch number after the factory for the reinspection and ultrasonic testing and visual inspection. Materials the reinspection projects including: chemical composition, tensile test, cold bend test, impact test. For more than 40 mm thick steel plate, because there is easy cause thick plate weld structure form of lamellar tearing, steel of thickness greater than 40 mm Z to the performance test. 
High strength bolt torque coefficient according to the factory batch number, make its performance meet the requirements. 
When the welding materials into the factory check carefully, mechanical properties and chemical composition of deposited metal the reinspection. 
Measuring instruments must be through the acceptance of legal units of measurement, and in the period of validity, the use of steel tape must be qualified through check the same steel tape.

1.2 the steel structure manufacture process quality assurance measures
(1) the lofting, pay attention to the reserved production welding shrinkage when blanking, before blanking bending or other material deformation should be corrected in advance.(2) the bolt hole set pattern, to guarantee the size position precision. 
(3) steel column head tight interface USES the end milling machining, milling end control processing surface and the center line of the vertical degree.(4) during welding in strict accordance with the instruction, welding procedure qualification for welding procedure qualification, according to the welding procedure qualification welding technology parameters, the implementation of the welding. Welders must receive pre-job training, should by the exam and obtained the certificate of approval rear can engage in the welding work. Flux by 350  baking 2 h. Shall be used for a small amount of manual welding, the welding electrode to by 350  baking 1 h before use, in the constant temperature box along with it. The implementation of preventive measures of welding deformation and internal stress during welding, choose the reasonable welding sequence and
Direction. Steel plate welding preheating before welding and heat treatment after welding measures. 
(5) to improve the quality of the finished product inspection
To strengthen the inspection of connection parts: for visual check all welding joint in construction. Check whether each joint surface dimension and construction.
To finish machining components in addition to the 100% for visual inspection, one on the drawing requirements, secondary weld ultrasonic testing in accordance with requirements. By testing to find defects such as delamination, slag welding area, to ensure the quality of welding. 
Weld inspection
Component completely after welding, except for visual inspection of weld ultrasonic testing according to requirement to weld to the factory, ultrasonic inspection check content: 100% level of full penetration welds, class 2 20% of full penetration weld.


1.3 the steel structure installation quality control

(1) transportation to the scene, the scene are jointly hold people together with the site supervision engineer recheck, review focused on the overall component parts of the deformation and is closely related to the installation precision of parts size, to find nonconforming items timely feedback to the factory for repair. 
(2) the measuring instrument, lasers, steel tape before use to check by the measuring department qualified rear can use.(3) the steel structure before installation, the pillar axis, infrastructure and elevation axes, etc. Bolt installation pouring concrete, measuring personnel tracking monitoring, found that the problem timely correcting, strengthen the review work measuring unreeling. 
(4) piled up and lifting transportation in component protection, prevent deformation. 
(5) pay attention to the measurement datum: when measuring axis positioning of each pillar should strictly on the basis of the control axis to civil led in the past, the next section pillars line shall not be used as in the previous section column axis positioning. 
(6) steel structure column in place immediately after the correction, fixed. On the day of the installation of steel members shall be fixed tightly.


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