In order to reduce the negative error of high-pressure
alloy steel pipe, so we have to deal with the existing situation under high pressure alloy pipe negative error method can only be determined first of its size. For example, 8-12 high-pressure alloy steel maximum agreed negative duty value of -7%, accounting diameter d must first determine the negative duty rate K value.
K value is too small, will make the inner diameter of the negative error scale is not fully utilized, K value is too large, and can not help but form part of the inner diameter scale beyond the normative rule of the lower limit, fail to achieve the strength of the rules of the rules and judged as unqualified. The existing technical control level, including the average diameter of the inner diameter and the standard deviation, the average of the strength and its standard deviation and so on to determine the K value.
K value of 30%, the value of the product diameter d with the nominal diameter of the steel plus the coefficient of 1.274 and the negative error of the utilization of steel, the difference between the negative error of the bar, the nominal cross-sectional area of the steel and then open the square to determine. According to the national standard rules of the horizontal rib distance scale and the product stick before the use of the number of sets of rules, the rules of the German specifications of the rebar roll circumference direction of the number of transverse ribs for the new roller grooving supply basis. Timely to the quality inspection staff to understand the weight of the product value, timely adjustment to ensure that the negative value of the official value of the national standard value.
